Paper-Based In-Situ Gold Nanoparticle Synthesis for Colorimetric, Non-Enzymatic Glucose Level Determination (original) (raw)
Related papers
Detection of glucose using gel-templated gold nanostructured electrodes
A precise monitoring of glucose level in blood is of high importance in clinical medicine, thus, sensitive, rapid and reliable methods for its detection are required. In this work, gelatin templated gold nanostructures were fabricated in order to improve the sensitivity of glucose analysis. SEM and AFM were used for characterization of the created surfaces. Glucose was detected by a direct electrochemical oxidation during cyclic voltammetry in alkaline solution. Limit of detection of 10 μM was achieved in aqueous samples. The sensor was also able to detect real concentration of glucose in deproteinised human serum with negligible effect of interferents. All results were verified by commercial glucometer and the standard kit for photometric detection of glucose.
Amino Coated Gold Nanorods Based Amperometric Glucose Detection
Citrate capped gold nanoseeds of uniform size and shape were prepared and used for CTAB-assisted growth of gold nanorods. Further, shape and size dependent hydrodynamic sedimentation behavior of nanostructure is exploited for separation of gold nanorods from mixture containing particles of different shape and size. The surface functionalization of gold nanorods with amino acids allows its efficient interaction with the enzyme and makes it a promising platform for applications including medical diagnostics and sensing devices. Further, the biosensing efficiency of the glucose biosensor fabricated by immobilizing glucose oxidase (GOx) onto gold nanorods was investigated. Under optimum conditions, the fabricated biosensor showed low detection limit, excellent storage stability and high sensitivity. The biosensor has a wide linear range for the detection of glucose from 5mM to 40mM with 6 s response time. The retained activity of glucose oxidase ensures the biocompatibility of amino coa...
Sensitive detection of glucose based on gold nanoparticles assisted silver mirror reaction
We developed a simple, non-enzymatic approach for the colorimetric detection of glucose based on a gold nanoparticles (Au NPs) assisted silver mirror reaction (AuSMR). The linear range of the concentration of glucose is from 0.04 mM to 1 mM, and the lowest concentration that can be distinguished by the naked eye is 10 nM. This approach has been successfully used for detecting glucose in serum.
Sensing and Bio-Sensing Research, 2019
Gold nanostars are being utilized more regularly in the field of nanodiagnostics. The modified seedless synthetic method comprised of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) synthesized with the addition of silver nitrate was applied for a biosensor application. The colorimetric ability of these newly synthesized nanostars showed to be more sensitive and more visually colorful than the HEPES gold nanostars synthesized without silver nitrate. It was observed that the gold nanostar colorimetric assay could be tailored for a specific application using either hydroxylamine or sodium hydroxide as colorimetric catalysts. Upon the attachment of glucose oxidase to the gold nanostars, glucose was measured by its oxidation and the generated hydrogen peroxide resulted in a sufficient color gradient that clearly distinguished different concentrations. Added to the color changes was the spectrophotometric localized surface plasmon resonance peak shifts in response to different glucose concentrations. In conclusion, the reported nanostars showed great potential as a good biosensing candidate.
Noninvasive glucose measurement by fluorescence quenching of non toxic gold nanoparticles
Optics & Laser Technology, 2014
Effects of interaction of human body compatible gold nanoparticles with glucose on fluorescence emission spectra of the nanoparticles are investigated experimentally. It is observed that nanoparticles' fluorescence peak quenches and blue shifted because of such interaction. This procedure is sensitive even to low difference of glucose concentration. The results suggest that glucose could seriously affect the optical properties of gold nanoparticles. Furthermore, a linear range of relative shift of different fluorescence spectrum's peaks is obtained. Furthermore, comparison of fluorescence and absorption results shows that the former technique is as much as 20 times more sensitive to the variation of glucose concentration.
Paper-Based Bioassays Using Gold Nanoparticle Colorimetric Probes
Analytical Chemistry, 2008
The majority of bioassays utilize thermosensitive reagents (e.g., biomolecules) and laboratory conditions for analysis. The developing world, however, requires inexpensive, simple-to-perform tests that do not require refrigeration or access to highly trained technicians. To address this need, paper-based bioassays using gold nanoparticle (AuNP) colorimetric probes have been developed. In the two prototype DNase I and adenosine-sensing assays, blue (or black)-colored DNA-cross-linked AuNP aggregates were spotted on paper substrates. The addition of target DNase I (or adenosine) solution dissociated the gold aggregates into dispersed AuNPs, which generated an intense red color on paper within one minute. Both hydrophobic and (poly(vinyl alcohol)-coated) hydrophilic paper substrates were suitable for this biosensing platform; by contrast, uncoated hydrophilic paper caused "bleeding" and premature cessation of the assay due to surface drying. The assays are surprisingly thermally stable. During preparation, AuNP aggregate-coated papers can be dried at elevated temperatures (e.g., 90°C) without significant loss of biosensing performance, which suggests the paper substrate protects AuNP aggregate probes from external nonspecific stimuli (e.g., heat). Moreover, the dried AuNP aggregate-coated papers can be stored for at least several weeks without loss of the biosensing function. The combination of paper substrates and AuNP colorimetric probes makes the final products inexpensive, low-volume, portable, disposable, and easyto-use. We believe this simple, practical bioassay platform will be of interest for use in areas such as disease diagnostics, pathogen detection, and quality monitoring of food and water.
Au nanocorals are grown on gold screen-printed electrodes (SPEs) by using a novel and simple one-step electro-deposition process. Scanning electron microscopy was used for the morphological characterization. The devices were assembled on a three-electrode SPE system, which is flexible and mass producible. The electroactive surface area, determined by cyclic voltammetry in sulphuric acid, was found to be 0.07 ± 0.01 cm 2 and 35.3 ± 2.7 cm 2 for bare Au and nanocoral Au, respectively. The nanocoral modified SPEs were used to develop an enzymatic glucose biosensor based on H 2 O 2 detection. Au nanocoral electrodes showed a higher sensitivity of 48.3 ± 0.9 μA/ (mM cm 2) at +0.45 V vs Ag|AgCl compared to a value of 24.6 ± 1.3 μA/(mM cm 2) at +0.70 V vs Ag|AgCl obtained with bare Au electrodes. However, the modified electrodes have indeed proven to be extremely powerful for the direct detection of glucose with a non-enzymatic approach. The results confirmed a clear peak observed by using nanocoral Au electrode even in the presence of chloride ions at physiological concentration. Amperometric study carried out at + 0.15 V vs Ag | AgCl in the presence of 0.12 M NaCl showed a linear range for glucose between 0.1 and 13 mM.
International Journal of Molecular Sciences
Glucose oxidase (GOx)-based electrodes are important for bioelectronics, such as glucose sensors. It is challenging to effectively link GOx with nanomaterial-modified electrodes while preserving enzyme activity in a biocompatible environment. To date, no reports have used biocompatible food-based materials, such as egg white proteins, combined with GOx, redox molecules, and nanoparticles to create the biorecognition layer for biosensors and biofuel cells. This article demonstrates the interface of GOx integrated with egg white proteins on a 5 nm gold nanoparticle (AuNP) functionalized with a 1,4-naphthoquinone (NQ) and conjugated with a screen-printed flexible conductive carbon nanotube (CNT)-modified electrode. Egg white proteins containing ovalbumin can form three-dimensional scaffolds to accommodate immobilized enzymes and adjust the analytical performance. The structure of this biointerface prevents the escape of enzymes and provides a suitable microenvironment for the effective...