Ultrasensitive and selective nonenzymatic detection of glucose using AuNP embedded polymeric nanostructures

Zeynep Altintas, Institute of Chemistry, Technical University of Berlin, Berlin, Germany (zeynep.altintas@tu-berlin.de)

Diabetes is a chronical and serious disease affecting millions of people. The chronic complications of diabetes include end-stage renal disease, accelerated development of cardiovascular disease, limb amputations, and loss of visual acuity. These complications cause the excess morbidity and mortality in individuals with diabetes. There is currently no permanent cure for diabetes; however, treatment to reduce the symptoms and complications is possible by the aid of medication and blood sugar monitoring [1]. Molecularly imprinted polymers (MIPs) can be synthesized and used as molecular receptors for specific recognition of glucose. Nevertheless, the MIP-based sensors are often lack of desired sensitivity for the quantification of disease biomarkers in human body fluids. Hence, we embedded gold nanoparticles in MIP matrix to improve the conductivity and sensitivity of the sensor surface to measure trace amounts of glucose in human serum.

The MIPs were synthesized on gold wire by a multistep amperometry technique using o-phenylenediamine as monomer and glucose as template molecule at 1:1 molar ratio [2]. An optimum concentration of previously synthesized gold nanoparticles was added to this mixture and the polymerization reaction was performed in one step. The template molecules were then removed from the polymer network by alkaline treatment and the empty cavities, corresponding to glucose, were obtained. The MIP electrode was exposed to glucose in buffer or human serum for the rebinding studies

Electrochemical and atomic force microscopy techniques confirmed the successful fabrication of the MIP sensor under optimal conditions. The glucose rebinding studies were performed using voltammetry methods in a concentration range of 0.00125‒0.32 µM. The MIP sensor without gold nanoparticles could not detect glucose even at much higher concentrations (e.g. 1 µM). The sensor showed a low level of cross-reaction with reference molecules, confirming the target specificity of molecular receptors.

The results of electrochemical sensor showed that we can produce ultrasensitive cavities in polymer matrix and quantify trace amounts of glucose, thanks to gold nanoparticles within the matrix. The presence of gold nanoparticles in the polymer network significantly improved the conductivity of the polymer film and led to a high sensitivity for glucose detection even in human serum.

References

1. Altintas, Z. Biosensors and Nanotechnology: Applications in Health Care Diagnostics, John Wiley & Sons 2018. Hoboken, USA.


2. Waffo, A.; Yesildag, C.; Caserta, G.; Katz, S.; Zebger, I.; Lensen, M.; Wollenberger, U.; Scheller, F.; Altintas, Z. Sensors and Actuators B: Chem. 2018, 275, 163–173.
   

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Abstract Reference & Short Personal Biography of Presenting Author

Dr. Zeynep Altintas is the head of the Biosensors and Receptor Development Group at the Technical University of Berlin, Germany. Her background is biomedical engineering and biotechnology. She leads an interdisciplinary research group in the domain of optical, piezoelectric and electrochemical biosensors, bioreceptor development, and molecular modelling. Her specialization also includes but not limited to implementation of biosensors for the diagnosis of disease biomarkers, pharmaceuticals, and food and environmental pathogens. She has more than 100 publications in these fields, including a book, journal articles, book chapters, patent applications, and conference papers. She has delivered numerous invited talks at international conferences and world-renowned institutes. She has built a reputation in her areas of expertise that is recognized by several international awards to her research. She serves as an expert reviewer for EU and Wisconsin Groundwater Coordinating Council (USA) funded projects, in addition to acting as an editorial board member and a reviewer for several important journals in her areas of expertise. She is also a member of the Royal Society of Chemistry