Juanita Hughes | Queensland University of Technology (original) (raw)

Videos by Juanita Hughes

This video shows me using the gold nanoparticle production method I used. Notice the speed of col... more This video shows me using the gold nanoparticle production method I used. Notice the speed of colour change. The change was so rapid that I had to film it to measure.

Papers by Juanita Hughes

PLOS ONE, Jul 30, 2013

In Australia and increasingly worldwide, methamphetamine is one of the most commonly seized drugs... more In Australia and increasingly worldwide, methamphetamine is one of the most commonly seized drugs analysed by forensic chemists. The current well-established GC/MS methods used to identify and quantify methamphetamine are lengthy, expensive processes, but often rapid analysis is requested by undercover police leading to an interest in developing this new analytical technique. Ninety six illicit drug seizures containing methamphetamine (0.1%-78.6%) were analysed using Fourier Transform Infrared Spectroscopy with an Attenuated Total Reflectance attachment and Chemometrics. Two Partial Least Squares models were developed, one using the principal Infrared Spectroscopy peaks of methamphetamine and the other a Hierarchical Partial Least Squares model. Both of these models were refined to choose the variables that were most closely associated with the methamphetamine % vector. Both of the models were excellent, with the principal peaks in the Partial Least Squares model having Root Mean Square Error of Prediction 3.8, R 2 0.9779 and lower limit of quantification 7% methamphetamine. The Hierarchical Partial Least Squares model had lower limit of quantification 0.3% methamphetamine, Root Mean Square Error of Prediction 5.2 and R 2 0.9637. Such models offer rapid and effective methods for screening illicit drug samples to determine the percentage of methamphetamine they contain.

PLOS ONE, Jul 30, 2013

Talanta, Dec 1, 2014

Ultra sensitive label free surface enhanced Raman spectroscopy method for the detection of biomol... more Ultra sensitive label free surface enhanced Raman spectroscopy method for the detection of biomolecules. Talanta, 130, pp. 20-25.

Talanta, Dec 1, 2014

This poster was presented at The Engagement Australia Next Steps Conference 2012 - Student Showca... more This poster was presented at The Engagement Australia Next Steps Conference 2012 - Student Showcase Poster Session. It outlines an example of the benefits of student/industry engagement for both students and their industry partner. It was an industry based research project which I did as an undergraduate chemistry/forensic science student. This subject was in replacement of the standard chemical research final semester project required for all chemistry majors. It briefly outlines results and enumerates the benefits both personally and to the industry partner.

from published article: Rapid Quantification of Methamphetamine: Using Attenuated Total ... more from published article: Rapid Quantification of Methamphetamine: Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Chemometrics Hughes J, Ayoko G, Collett S, Golding G (2013) Rapid Quantification of Methamphetamine: Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Chemometrics. PLoS ONE 8(7): e69609. doi:10.1371/journal.pone.0069609 figure doi:10.1371/journal.pone.0069609.g004</p

Raman spectroscopy has recently achieved considerable interest for biomedical diagnosis and promi... more Raman spectroscopy has recently achieved considerable interest for biomedical diagnosis and promising and innovative therapies. 1 The emergence of compact laser sources, more sensitive detection equipment and portable instrumentation have all contributed to this interest. Here we report an ultrasensitive method for detecting bio-active compounds in biological samples by means of functionalized nanoparticles interrogated by surface enhanced Raman spectroscopy (SERS). This method is applicable to the recovery and detection of many diagnostically important peptidyl analytes such as insulin, human growth hormone (somatotropin), mitogenic polypeptide growth factors (IGFs) and erythropoietin (EPO), as well as many small molecule analytes and metabolites. Our method was developed using the EPO system to demonstrate its utility in a complex yet well-defined biological system. Recombinant human EPO (rHuEPO) and EPO analogues have successfully been used to treat anaemia in end-stage renal fai...

This thesis developed a new method for measuring extremely low amounts of organic and biological ... more This thesis developed a new method for measuring extremely low amounts of organic and biological molecules, using Surface enhanced Raman Spectroscopy. This method has many potential applications, e.g. medical diagnosis, public health, food provenance, antidoping, forensics and homeland security. The method development used caffeine as the small molecule example, and erythropoietin (EPO) as the large molecule. This method is much more sensitive and specific than currently used methods; rapid, simple and cost effective. The method can be used to detect target molecules in beverages and biological fluids without the usual preparation steps.

Introduction Natural product provenance is important in the food, beverage and pharmaceutical ind... more Introduction Natural product provenance is important in the food, beverage and pharmaceutical industries, for consumer confidence and with health implications. Raman spectroscopy has powerful molecular fingerprint abilities. Surface Enhanced Raman Spectroscopy’s (SERS) sharp peaks allow distinction between minimally different molecules, so it should be suitable for this purpose. Methods Naturally caffeinated beverages with Guarana extract, coffee and Red Bull energy drink as a synthetic caffeinated beverage for comparison (20 µL ea.) were reacted 1:1 with Gold nanoparticles functionalised with anti-caffeine antibody (ab15221) (10 minutes), air dried and analysed in a micro-Raman instrument. The spectral data was processed using Principle Component Analysis (PCA). Results The PCA showed Guarana sourced caffeine varied significantly from synthetic caffeine (Red Bull) on component 1 (containing 76.4% of the variance in the data). See figure 1. The coffee containing beverages, and in pa...

We have developed an explanation for ultra trace detection found when using Au/Ag SERS nanopartic... more We have developed an explanation for ultra trace detection found when using Au/Ag SERS nanoparticles linked to biochemical affinity tags, e.g. antibodies. The nanoparticle structure is not as usually assumed and the aggregated nanoparticles constitute hot spots that are indispensable for these very low levels of analyte detection, even more so when using a direct detection method.

Here we report an ultrasensitive method for detecting bio-active compounds in biological samples ... more Here we report an ultrasensitive method for detecting bio-active compounds in biological samples by means of functionalised nanoparticles interrogated by surface enhanced Raman spectroscopy (SERS). This method is applicable to the recovery and detection of many diagnostically important peptidyl analytes such as insulin, human growth hormone, growth factors (IGFs) and erythropoietin (EPO), as well as many small molecule analytes and metabolites. Our method, developed to detect EPO, demonstrates its utility in a complex yet well defined biological system. Recombinant human EPO (rhEPO) and EPO analogues have successfully been used to treat anaemia in end-stage renal failure, chronic disorders and infections, cancer and AIDS. Current methods for EPO testing are lengthy, laborious and relatively insensitive to low concentrations. In our rapid screening methodology, gold nanoparticles were functionalised with anti-EPO antibodies to provide very high selectivity towards the EPO protein in ...

comparision of UV_VIS results for the tradition Turkevich method and this new method by Xia et al... more comparision of UV_VIS results for the tradition Turkevich method and this new method by Xia et al. also included is the result of nanoparticles prepared without the trace silver [I].

Typical ATR-FTIR spectra of Methamphetamine, a) High concentration {78.6%} b) Low concentration {... more Typical ATR-FTIR spectra of Methamphetamine, a) High concentration {78.6%} b) Low concentration {10.3% cut with MSM (Methylsulphonylmethane)}.

Figure 2: HPCA loadings plot: component 1 versus component 2. (Dotted triangle shows Methamphetam... more Figure 2: HPCA loadings plot: component 1 versus component 2. (Dotted triangle shows Methamphetamine concentration direction in scores plot)

PLOS ONE, Jul 30, 2013

Talanta, Dec 1, 2014

demonstration of gold nanoparticles modified method, See also UV/VIs of traditional turkevich met... more demonstration of gold nanoparticles modified method, See also UV/VIs of traditional turkevich method vs this new method and the method without the trace silver[I],TEM, and graphs of size and x,y ratio of these nanoparticles.

It outlines an example of the benefits of student/industry engagement for both students and their industry partner. It was an industry based research project which I did as an undergraduate chemistry/forensic science student. This subject was in replacement of the standard chemical research final semester project required for all chemistry majors. It briefly outlines results and enumerates the benefits both personally and to the industry partner.

The ultra trace detection of both simple and large organic biomolecules is sought after for many ... more The ultra trace detection of both simple and large organic biomolecules is sought after for many different applications. The aim of this research was to develop a simple, rapid and cost-effective technique for the detection of ultra trace amounts of simple organic molecules as well as complex biomolecules, using functionalised Surface Enhanced Raman Spectroscopy (SERS). Two models were developed using caffeine and erythropoietin (EPO) respectively.
Caffeine, the world’s most widely used legal stimulant, is found in both beverages and pharmaceuticals. With its ubiquity, its assay is an important chemical analysis. Caffeine serves as an excellent simple organic molecule exemplar for this analytical technique.
Erythropoietin is a complex protein hormone produced by the kidneys to initiate red blood cell production and found in blood serum and urine. Detection and quantification of both human EPO and recombinant human EPO (rHuEPO) is required for medical purposes. Their distinction is also required, as rHuEPO is banned by both the World Anti-Doping Agency (WADA) and in animal racing. RHuEPO’s proscribed use by athletes has been well documented in several infamous cases, e.g., in cycling. As a complex protein, EPO is also a valuable complex biomolecule exemplar for this technique.
For this work, antibody functionalised nanoparticles were developed and characterized, reacted with the analyte solutions, and then characterized by Raman spectroscopy. This thesis presents the results of the nanoparticle characterization, the Raman spectra, and the univariate statistical and/or chemometrics analysis.
It demonstrates the ability of this new technique to detect ultra low levels of the nominated analytes with significant improvement over existing methods. Caffeine detection was improved from 2×10-4 g (FT-Raman) down to 2×10-13 g. The detection of EPO improved from 7×10-11 g (IEF) down to 3×10-16 g.
This novel technique quantifies the analytes in trace amounts, encompassing those levels required for the analysis of the nominated analytes (2×10-10 M to 3.5×10-13 M for EPO and 1×10-4 M to 1×10-9 M for caffeine), with application in many fields (such as, food analysis, clinical diagnostics, and in the racing and sports industries). Moreover it distinguishes between human EPO and rHuEPO, with a substantial improvement on current techniques, 71% (IEF) and 40% (MAIIA); distinguishing rHuEPO in urine at 2.5% of the total EPO. And so has widespread applicability for the ultra trace analysis of biomolecules.