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

Abstract

In this work, a novel amperometric biosensor based on gold nanoparticles anchored on reduced graphene oxide (RGO-AuNPs) and l-lactate dehydrogenase (LDH) was developed for the sensing of l-lactate. Firstly, the RGO-AuNPs modified screen printed electrodes were tested for NADH detection showing a wide dynamic range and a low detection limit. Next, the biosensor was constructed by incorporating both enzyme and RGO-AuNPs in a sol gel matrix derived from tetrametoxysilane and methyltrimetoxysilane. The enzyme loading, working pH, and coenzyme concentration were optimized. The biosensor linearly responded to l-lactate in the range of 10µM-5mM and showed a good specific sensitivity of 154µA/mMcm(2) with a detection limit of 0.13µM. This was accompanied by good reproducibility 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 l-ascorbate. Our LDH/RGO-AuNPs/SPCE based biosensor thus performs as electrochemical device for the detection of l-lactate as a viable early cancer bio-marker.

Electrochemical biosensors based on nanomodified screen-printed electrodes: Recent applications in clinical analysis

“…Composite of reduced graphene oxide and gold nanoparticles were exploited for lactate biosensor development using L-lactate dehydrogenase as biocomponent [19]. Using the applied potential of +480 mV (vs Ag/AgCl) and NAD + concentration of 3 mM, a calibration curve with a linear range between 0.01-5 mM was obtained, covering the normal and pathological L-lactate levels.…”

“…Another advantage during the sensor production phase is represented by the possibility of using very small volumes of solution to be applied on the electrode surface. For example, for classic SPEs it is usually sufficient (when spontaneous thiol-gold linkage is used) to cast a drop of few microliters (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) of the thiol-labeled oligo on the surface of the gold-ink electrode to achieve well-ordered SAMs. This is usually not possible with conventional rod gold electrodes which generally require larger volumes.…”

Nanoparticles in biomedical applications

“…Metallic nanoparticles such as gold (Au) possess unique electronic and optical properties as well as chemical inertness and its ability for surface functionalisation which is due to the negative charge on its surface [112][113][114]. Gold's unique electronic and optical properties have resulted in its use in biosensors [115][116][117][118] and bioimaging [119][120][121][122][123] as well as photothermal therapy [121][122][123][124][125]. Gold's ease at functionalisation with organic molecules allows for conjugation with ligands, antibodies or drug molecules for active or passive drug delivery [126][127][128][129][130].…”

“…This review investigates other nanosystems such as metallic nanoparticles like gold (Au) [112][113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128][129][130] and silver (Ag) , bimetallic nanoparticles like iron cobalt (Fe-Co) [78][79][80][92][93][94][95][96][97]108,109] and iron platinum (Fe-Pt) [155][156][157][158][159][160][161][162][163][164][165][166][167][168][169][170][171][172] and metal oxides including titanium dioxide (TiO 2 ) [1...…”

Nanomaterial-based biosensors for biological detections

“…27 AuNPs have also been coupled with other nanomaterials such as GR and CNTs for the detection of different analytes. In a study by Azzouzi et al, 28 a biosensor was developed for measuring L-lactate using AuNPs anchored on reduced graphene oxide (RGO-AuNPs) and L-lactate dehydrogenase (LDH), over a screen-printed carbon electrode. RGO-AuNPs were prepared by adding RGO to HAuCl 4 solution.…”