Disposable and portable gold nanoparticles modified - laser-scribed graphene sensing strips for electrochemical, non-enzymatic detection of glucose

Abstract

Glucose is one of the most important metabolites and a primary nutrient in human body metabolism. Abnormal levels of glucose can cause diabetes mellitus and related complications. Here, we developed a disposable and portable non-enzymatic glucose sensor strip based on gold-nanoparticles (AuNPs)-modified laser-scribed graphene electrode (LSGE). Disposable LSGEs, with a highly porous structure, were fabricated by laser scribing on a commercially available polyimide plastic sheets, followed by electrodepositing of AuNPs, that are electrocatalytic for glucose oxidation. The laser scribing process was optimised in term of laser power, laser speed and pulse per inch (PPI). The effect of number of the electrochemical deposition cycles of AuNPs on LSGE was also investigated and optimised. The sensor provides a linear detection range for the glucose concentrations between 10 µM to 10 mM with a limit of detection of 6.3 µM and shows a good selectivity towards interfering agents, such as urea L-ascorbic acid, uric acid, dopamine, and Na+. The LSGE/AuNP strips have a potential to be used as disposable glucose sensor strips for point-of-care glucose measurements, including self-monitoring and nutrition management.