Shah Mukim Uddin | University of Melbourne (original) (raw)
Papers by Shah Mukim Uddin
Biosensors & bioelectronics, Jan 31, 2017
Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and... more Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60min. Then, the amplicons of the LAMP reaction were detected using the calcein ...
Sensors, 2015
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis d...
Biosensors, 2022
The magnetic beads detection-based immunoassay, also called magneto-immunoassay, has potential ap... more The magnetic beads detection-based immunoassay, also called magneto-immunoassay, has potential applications in point-of-care testing (POCT) due to its unique advantage of minimal background interference from the biological sample and associated reagents. While magnetic field detection technologies are well established for numerous applications in the military, as well as in geology, archaeology, mining, spacecraft, and mobile phones, adaptation into magneto-immunoassay is yet to be explored. The magnetic field biosensors under development tend to be multilayered and require an expensive fabrication process. A low-cost and affordable biosensing platform is required for an effective point-of-care diagnosis in a resource-limited environment. Therefore, we evaluated a single-layered magnetic biosensor in this study to overcome this limitation. The shape-induced magnetic anisotropy-based planar hall effect sensor was recently developed to detect a low-level magnetic field, but was not ex...
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10 −3 ng/µL with different DNA concentrations of Salmonella
International Conference on Biomedical and Health Informatics, 2018
Salmonellosis caused by the bacteria in the genus Salmonella remains the most important foodborne... more Salmonellosis caused by the bacteria in the genus Salmonella remains the most important foodborne disease in both developing and developed countries. Since several decades various microbial detection and quantification methods have been developed. One of recently developed gene amplification method is loop-mediated isothermal amplification (LAMP) which has been developed on tube-based platform. To facilitate the detection of pathogenic diseases in remote areas, a microfluidic platform has been developed called lab-on-a-CD. This paper presents an improved endpoint detection system for LAMP on Lab-on-a-CD platform. A set of ultraviolet (UV) emitter and color sensor have been used in this detection system to detect the emission level of LAMP amplicons. A LAMP assay has been performed with Salmonella bacteria DNA and calibrated the duty cycle of UV emitter to optimize the amplicons detection system.
HLA-B*15:02 screening before administering carbamazepine is recommended to prevent life-threateni... more HLA-B*15:02 screening before administering carbamazepine is recommended to prevent life-threatening hypersensitivity. However, the unavailability of a point-of-care device impedes this screening process. Our research group previously developed a two-step HLA-B*15:02 detection technique utilizing loop-mediated isothermal amplification (LAMP) on the tube, which requires two-stage device development to translate into a portable platform. Here, we report a heater-integrated lab-on-a-chip device for the LAMP amplification, which can rapidly detect HLA-B alleles colorimetrically. A gold-patterned micro-sized heater was integrated into a 3D-printed chip, allowing microfluidic pumping, valving, and incubation. The performance of the chip was tested with color dye. Then LAMP assay was conducted with human genomic DNA samples of known HLA-B genotypes in the LAMP-chip parallel with the tube assay. The LAMP-on-chip results showed a complete match with the LAMP-on-tube assay, demonstrating the d...
Sensors, Aug 14, 2019
Pre-treatment screening of individuals for human leukocyte antigens (HLA) HLA-B*57:01 is recommen... more Pre-treatment screening of individuals for human leukocyte antigens (HLA) HLA-B*57:01 is recommended for the prevention of life-threatening hypersensitivity reactions to abacavir, a drug widely prescribed for HIV treatment. However, the implementation of screening in clinical practice is hindered by the slow turnaround time and high cost of conventional HLA genotyping methods. We have developed a biosensor platform using interdigitated electrode (IDE) functionalized with a monoclonal antibody to detect cells expressing HLA-B*57:01. This platform was evaluated using cell lines and peripheral blood mononuclear cells expressing different HLA-B alleles. The functionalized IDE sensor was able to specifically capture HLA-B*57:01 cells, resulting in a significant change in the impedance magnitude in 20 min. This IDE platform has the potential to be further developed to enable point-of-care HLA-B*57:01 screening.
Sensors
Thin-film magneto-impedance (MI) biosensors have attracted significant attention due to their hig... more Thin-film magneto-impedance (MI) biosensors have attracted significant attention due to their high sensitivity and easy miniaturization. However, further improvement is required to detect weak biomagnetic signals. Here, we report a meander thin-film biosensor preparation to investigate the fabrication parameters influencing the MI effect. Specifically, we hypothesized that an optimal film thickness and sensing area size ratio could be achieved to obtain a maximum MI ratio. A meander multilayer MI biosensor based on a NiFe/Cu/NiFe thin-film was designed and fabricated into 3-, 6-, and 9-turn models with film thicknesses of 3 µm and 6 µm. The 9-turn biosensor resembled the largest sensing area, while the 3- and 6-turn biosensors were designed with identical sensing areas. The results indicated that the NiFe film thickness of 6 µm with a sensing area size of 14.4 mm2 resembling a 9-turn MI biosensor is the optimal ratio yielding the maximum MI ratio of 238%, which is 70% larger than th...
Scientific Reports
Malaria elimination is a global public health priority. To fulfil the demands of elimination diag... more Malaria elimination is a global public health priority. To fulfil the demands of elimination diagnostics, we have developed an interdigitated electrode sensor platform targeting the Plasmodium falciparum Histidine Rich Protein 2 (PfHRP2) protein in saliva samples. A protocol for frequency-specific PfHRP2 detection in phosphate buffered saline was developed, yielding a sensitivity of 2.5 pg/mL based on change in impedance magnitude of the sensor. This protocol was adapted and optimized for use in saliva with a sensitivity of 25 pg/mL based on change in resistance. Further validation demonstrated detection in saliva spiked with PfHRP2 from clinical isolates in 8 of 11 samples. With a turnaround time of ~2 hours, the label-free platform based on impedance sensors has the potential for miniaturization into a point-of-care diagnostic device for malaria elimination.
A B S T R A C T Outbreaks of foodborne diseases have become a global health concern; hence, many ... more A B S T R A C T Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60 min. Then, the amplicons of the LAMP reaction were detected using the calcein colorimetric method and further analysed via the developed electronic system interfaced with Bluetooth wireless technology to transmit the results to a smartphone. The system showed a limit of detection (LOD) of 3 × 10 −5 ng μL −1 DNA by analysing the colour change when tested with chicken meat spiked with the three pathogenic bacteria. Since the entire process was performed in a fully automated way and was easy to use, our microdevice is suitable for point-of-care (POC) testing with high simplicity, providing affordability and accessibility even to poor, resource-limited settings.
2013 International Conference on Informatics, Electronics and Vision (ICIEV), 2013
ABSTRACT In developing country like Bangladesh, the demand of electrical energy is very higher th... more ABSTRACT In developing country like Bangladesh, the demand of electrical energy is very higher than the available production. At present, the electricity supply deficiency is about 1500 to 2000 MW /day i.e. the total supply is 4000 to 4500 MW/day within the demand of 6000 MW/day for this reason power failure has become an acute problem in our country. To solve this energy crisis, it is Important to found alternative approaches. Recently Tidal power becomes most important and researchable topic in the world, especially the countries which are placed near sea or ocean. Bangladesh is situated between 20°34' and 26°38' north latitude, 88°01' & 92°41' east longitude with an area of 147570 sq.km. It has a 710 km of coastal line along the Bay of Bengal [13]. As Bangladesh has a long coastal line along the Bay of Bengal, so tidal energy technology can be used as one of the major reliable energy resource. In this paper an efficient tidal energy site is proposed based on analysis of technical as well as market data and the data is collected from Bangladesh Navy and different tidal current data chart. Finally based on tidal current condition of one of the efficient site, a MATLAB simulink simulation result is shown by proposed a suitable electrical generator.
Sensors and Actuators B: Chemical, Jun 4, 2016
Salmonellosis is one of the most common foodborne diseases caused by the genus Salmonella and is ... more Salmonellosis is one of the most common foodborne diseases caused by the genus Salmonella and is considered to be a significant global health concern. Therefore, the development of effective techniques for rapidly detecting Salmonella is fundamental in preventing foodborne outbreaks. This paper presents a lab-on-a-disc integrated loop mediated isothermal amplification (LAMP) on a microfluidic platform for Salmonella detection. We have developed a centrifugal microfluidic platform device in which the main steps in pathogen detection, reagent preparation, LAMP, and detection can be integrated onto a single microfluidic compact disc (CD). A forced convection heating source was used for wax valve actuation and temperature heating for the LAMP amplification, leading toward compactness and system miniaturization. The detection limit was 5 × 10−3 ng/μL DNA concentration when tested on tomatoes spiked with Salmonella. The whole procedure, from sample preparation (on the microfluidic CD) up to detection, was completed within 70 min using a fully automated process. The final detection step was performed via direct visual observation of the color change of the SYBR Green I dye. Our system offers a fast and automated molecular diagnostic platform, thereby reducing the need for skillful operators and expensive instrumentation. This developed portable device would have a wide range of potential biomedical applications, including foodborne pathogen detection and molecular diagnostics in developing countries.
Scientific Reports, Nov 9, 2015
The application of microfluidic devices in diagnostic systems is well-established in contemporary... more The application of microfluidic devices in diagnostic systems is well-established in contemporary research. Large specific surface area of microspheres, on the other hand, has secured an important position for their use in bioanalytical assays. Herein, we report a combination of microspheres and microfluidic disk in a unique hybrid platform for highly sensitive and selective detection of dengue virus. Surface engineered polymethacrylate microspheres with carefully designed functional groups facilitate biorecognition in a multitude manner. In order to maximize the utility of the microspheres' specific surface area in biomolecular interaction, the microfluidic disk was equipped with a micromixing system. The mixing mechanism (microballoon mixing) enhances the number of molecular encounters between spheres and target analyte by accessing the entire sample volume more effectively, which subsequently results in signal amplification. Significant reduction of incubation time along with considerable lower detection limits were the prime motivations for the integration of microspheres inside the microfluidic disk. Lengthy incubations of routine analytical assays were reduced from 2 hours to 5 minutes while developed system successfully detected a few units of dengue virus. Obtained results make this hybrid microsphere-microfluidic approach to dengue detection a promising avenue for early detection of this fatal illness.
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.
Biosensors & bioelectronics, Jan 31, 2017
Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and... more Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60min. Then, the amplicons of the LAMP reaction were detected using the calcein ...
Sensors, 2015
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis d...
Biosensors, 2022
The magnetic beads detection-based immunoassay, also called magneto-immunoassay, has potential ap... more The magnetic beads detection-based immunoassay, also called magneto-immunoassay, has potential applications in point-of-care testing (POCT) due to its unique advantage of minimal background interference from the biological sample and associated reagents. While magnetic field detection technologies are well established for numerous applications in the military, as well as in geology, archaeology, mining, spacecraft, and mobile phones, adaptation into magneto-immunoassay is yet to be explored. The magnetic field biosensors under development tend to be multilayered and require an expensive fabrication process. A low-cost and affordable biosensing platform is required for an effective point-of-care diagnosis in a resource-limited environment. Therefore, we evaluated a single-layered magnetic biosensor in this study to overcome this limitation. The shape-induced magnetic anisotropy-based planar hall effect sensor was recently developed to detect a low-level magnetic field, but was not ex...
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10 −3 ng/µL with different DNA concentrations of Salmonella
International Conference on Biomedical and Health Informatics, 2018
Salmonellosis caused by the bacteria in the genus Salmonella remains the most important foodborne... more Salmonellosis caused by the bacteria in the genus Salmonella remains the most important foodborne disease in both developing and developed countries. Since several decades various microbial detection and quantification methods have been developed. One of recently developed gene amplification method is loop-mediated isothermal amplification (LAMP) which has been developed on tube-based platform. To facilitate the detection of pathogenic diseases in remote areas, a microfluidic platform has been developed called lab-on-a-CD. This paper presents an improved endpoint detection system for LAMP on Lab-on-a-CD platform. A set of ultraviolet (UV) emitter and color sensor have been used in this detection system to detect the emission level of LAMP amplicons. A LAMP assay has been performed with Salmonella bacteria DNA and calibrated the duty cycle of UV emitter to optimize the amplicons detection system.
HLA-B*15:02 screening before administering carbamazepine is recommended to prevent life-threateni... more HLA-B*15:02 screening before administering carbamazepine is recommended to prevent life-threatening hypersensitivity. However, the unavailability of a point-of-care device impedes this screening process. Our research group previously developed a two-step HLA-B*15:02 detection technique utilizing loop-mediated isothermal amplification (LAMP) on the tube, which requires two-stage device development to translate into a portable platform. Here, we report a heater-integrated lab-on-a-chip device for the LAMP amplification, which can rapidly detect HLA-B alleles colorimetrically. A gold-patterned micro-sized heater was integrated into a 3D-printed chip, allowing microfluidic pumping, valving, and incubation. The performance of the chip was tested with color dye. Then LAMP assay was conducted with human genomic DNA samples of known HLA-B genotypes in the LAMP-chip parallel with the tube assay. The LAMP-on-chip results showed a complete match with the LAMP-on-tube assay, demonstrating the d...
Sensors, Aug 14, 2019
Pre-treatment screening of individuals for human leukocyte antigens (HLA) HLA-B*57:01 is recommen... more Pre-treatment screening of individuals for human leukocyte antigens (HLA) HLA-B*57:01 is recommended for the prevention of life-threatening hypersensitivity reactions to abacavir, a drug widely prescribed for HIV treatment. However, the implementation of screening in clinical practice is hindered by the slow turnaround time and high cost of conventional HLA genotyping methods. We have developed a biosensor platform using interdigitated electrode (IDE) functionalized with a monoclonal antibody to detect cells expressing HLA-B*57:01. This platform was evaluated using cell lines and peripheral blood mononuclear cells expressing different HLA-B alleles. The functionalized IDE sensor was able to specifically capture HLA-B*57:01 cells, resulting in a significant change in the impedance magnitude in 20 min. This IDE platform has the potential to be further developed to enable point-of-care HLA-B*57:01 screening.
Sensors
Thin-film magneto-impedance (MI) biosensors have attracted significant attention due to their hig... more Thin-film magneto-impedance (MI) biosensors have attracted significant attention due to their high sensitivity and easy miniaturization. However, further improvement is required to detect weak biomagnetic signals. Here, we report a meander thin-film biosensor preparation to investigate the fabrication parameters influencing the MI effect. Specifically, we hypothesized that an optimal film thickness and sensing area size ratio could be achieved to obtain a maximum MI ratio. A meander multilayer MI biosensor based on a NiFe/Cu/NiFe thin-film was designed and fabricated into 3-, 6-, and 9-turn models with film thicknesses of 3 µm and 6 µm. The 9-turn biosensor resembled the largest sensing area, while the 3- and 6-turn biosensors were designed with identical sensing areas. The results indicated that the NiFe film thickness of 6 µm with a sensing area size of 14.4 mm2 resembling a 9-turn MI biosensor is the optimal ratio yielding the maximum MI ratio of 238%, which is 70% larger than th...
Scientific Reports
Malaria elimination is a global public health priority. To fulfil the demands of elimination diag... more Malaria elimination is a global public health priority. To fulfil the demands of elimination diagnostics, we have developed an interdigitated electrode sensor platform targeting the Plasmodium falciparum Histidine Rich Protein 2 (PfHRP2) protein in saliva samples. A protocol for frequency-specific PfHRP2 detection in phosphate buffered saline was developed, yielding a sensitivity of 2.5 pg/mL based on change in impedance magnitude of the sensor. This protocol was adapted and optimized for use in saliva with a sensitivity of 25 pg/mL based on change in resistance. Further validation demonstrated detection in saliva spiked with PfHRP2 from clinical isolates in 8 of 11 samples. With a turnaround time of ~2 hours, the label-free platform based on impedance sensors has the potential for miniaturization into a point-of-care diagnostic device for malaria elimination.
A B S T R A C T Outbreaks of foodborne diseases have become a global health concern; hence, many ... more A B S T R A C T Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60 min. Then, the amplicons of the LAMP reaction were detected using the calcein colorimetric method and further analysed via the developed electronic system interfaced with Bluetooth wireless technology to transmit the results to a smartphone. The system showed a limit of detection (LOD) of 3 × 10 −5 ng μL −1 DNA by analysing the colour change when tested with chicken meat spiked with the three pathogenic bacteria. Since the entire process was performed in a fully automated way and was easy to use, our microdevice is suitable for point-of-care (POC) testing with high simplicity, providing affordability and accessibility even to poor, resource-limited settings.
2013 International Conference on Informatics, Electronics and Vision (ICIEV), 2013
ABSTRACT In developing country like Bangladesh, the demand of electrical energy is very higher th... more ABSTRACT In developing country like Bangladesh, the demand of electrical energy is very higher than the available production. At present, the electricity supply deficiency is about 1500 to 2000 MW /day i.e. the total supply is 4000 to 4500 MW/day within the demand of 6000 MW/day for this reason power failure has become an acute problem in our country. To solve this energy crisis, it is Important to found alternative approaches. Recently Tidal power becomes most important and researchable topic in the world, especially the countries which are placed near sea or ocean. Bangladesh is situated between 20°34' and 26°38' north latitude, 88°01' & 92°41' east longitude with an area of 147570 sq.km. It has a 710 km of coastal line along the Bay of Bengal [13]. As Bangladesh has a long coastal line along the Bay of Bengal, so tidal energy technology can be used as one of the major reliable energy resource. In this paper an efficient tidal energy site is proposed based on analysis of technical as well as market data and the data is collected from Bangladesh Navy and different tidal current data chart. Finally based on tidal current condition of one of the efficient site, a MATLAB simulink simulation result is shown by proposed a suitable electrical generator.
Sensors and Actuators B: Chemical, Jun 4, 2016
Salmonellosis is one of the most common foodborne diseases caused by the genus Salmonella and is ... more Salmonellosis is one of the most common foodborne diseases caused by the genus Salmonella and is considered to be a significant global health concern. Therefore, the development of effective techniques for rapidly detecting Salmonella is fundamental in preventing foodborne outbreaks. This paper presents a lab-on-a-disc integrated loop mediated isothermal amplification (LAMP) on a microfluidic platform for Salmonella detection. We have developed a centrifugal microfluidic platform device in which the main steps in pathogen detection, reagent preparation, LAMP, and detection can be integrated onto a single microfluidic compact disc (CD). A forced convection heating source was used for wax valve actuation and temperature heating for the LAMP amplification, leading toward compactness and system miniaturization. The detection limit was 5 × 10−3 ng/μL DNA concentration when tested on tomatoes spiked with Salmonella. The whole procedure, from sample preparation (on the microfluidic CD) up to detection, was completed within 70 min using a fully automated process. The final detection step was performed via direct visual observation of the color change of the SYBR Green I dye. Our system offers a fast and automated molecular diagnostic platform, thereby reducing the need for skillful operators and expensive instrumentation. This developed portable device would have a wide range of potential biomedical applications, including foodborne pathogen detection and molecular diagnostics in developing countries.
Scientific Reports, Nov 9, 2015
The application of microfluidic devices in diagnostic systems is well-established in contemporary... more The application of microfluidic devices in diagnostic systems is well-established in contemporary research. Large specific surface area of microspheres, on the other hand, has secured an important position for their use in bioanalytical assays. Herein, we report a combination of microspheres and microfluidic disk in a unique hybrid platform for highly sensitive and selective detection of dengue virus. Surface engineered polymethacrylate microspheres with carefully designed functional groups facilitate biorecognition in a multitude manner. In order to maximize the utility of the microspheres' specific surface area in biomolecular interaction, the microfluidic disk was equipped with a micromixing system. The mixing mechanism (microballoon mixing) enhances the number of molecular encounters between spheres and target analyte by accessing the entire sample volume more effectively, which subsequently results in signal amplification. Significant reduction of incubation time along with considerable lower detection limits were the prime motivations for the integration of microspheres inside the microfluidic disk. Lengthy incubations of routine analytical assays were reduced from 2 hours to 5 minutes while developed system successfully detected a few units of dengue virus. Obtained results make this hybrid microsphere-microfluidic approach to dengue detection a promising avenue for early detection of this fatal illness.
In recent years, many improvements have been made in foodborne pathogen detection methods to redu... more In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.