A novel amperometric biosensor based on gold nanoparticles anchored on reduced graphene oxide for sensitive detection of L-lactate tumor biomarker

摘要

In this work, a novel amperometric biosensor based on gold nanoparticles anchored on reduced\udgraphene oxide (RGO-AuNPs) and L-lactate dehydrogenase (LDH) was developed for the sensing of Llactate.\udFirstly, the RGO-AuNPs modified screen printed electrodes were tested for NADH detection\udshowing a wide dynamic range and a low detection limit. Next, the biosensor was constructed by\udincorporating both enzyme and RGO-AuNPs in a sol gel matrix derived from tetrametoxysilane and\udmethyltrimetoxysilane. The enzyme loading, working pH, and coenzyme concentration were optimized.\udThe biosensor linearly responded to L-lactate in the range of 10 μM - 5 mM and showed a good specific\udsensitivity of 154 μA/mM·cm2 with a detection limit of 0.13 μM. This was accompanied by good\udreproducibility and operational stability. Tests on artificial serum proved that L-lactate can be determined practically without interferences from commonly interfering compounds such as urate, paracetamol and\udL-ascorbate. Our LDH/RGO-AuNPs/SPCE based biosensor thus performs as electrochemical device for\udthe detection of L-lactate as a viable early cancer bio-marker.