| Title : An acetylcholinesterase-based biosensor for isoprocarb using a gold nanoparticles-polyaniline modified graphite pencil electrode - Rachmawati_2023_Anal.Sci__ |
| Author(s) : Rachmawati A , Sanjaya AR , Putri Y , Gunlazuardi J , Ivandini TA |
| Ref : Anal Sci , : , 2023 |
| Abstract : An analysis tool for isoprocarb has been successfully developed as a biosensor system based on enzymatic inhibition of acetylcholinesterase (AChE) by isoprocarb. A gold nanoparticles-polyaniline modified graphite pencil electrode (AuNPs-PANI-GPE) was utilized to detect the change of thiocholine in the presence of isoprocarb. This electrode was prepared by two cyclic voltammetry steps, including the electro-polymerization of aniline on a graphite pencil and the electro-deposition of gold nanoparticles on the polyaniline surface. Characterization performed by SEM-EDX indicates that 8-80 nm size of gold nanoparticles could be deposited on the surface of polyaniline-modified graphite pencil (PANI-GPE). Electrochemical characterization using cyclic voltammetry suggested that the active surface area of the prepared electrode was 0.17019 cm(2), which was about 4 times higher than (PANI-GPE) and 13 times higher than the unmodified GPE. Furthermore, an oxidation peak of thiocholine could be observed at the modified GPE at a potential of + 0.675 V (vs. Ag/AgCl), formed by an enzymatic reaction of AChE in the presence of acetylthiocholine. This peak current was found to linearly increase with acetylthiocholine concentrations, while in the presence of isoprocarb in a constant concentration of AChE and acetylthiocholine the peak linearly decreases. At the optimum condition of 0.1 M phosphate buffer solution pH 7.4 containing 0.1 M KCl; 100 mU/ml AChE; and 1 mM acetylthiocholine chloride in an inhibition and contact time of 25 and 15 min, respectively, a linear calibration curve of isoprocarb in the concentration range of 0.05-1.0 microM could be provided. Estimated limits of detection and quantifications of 0.1615 nM and 0.5382 nM, respectively, with a sensitivity of 1.7771 microA/microM.mm(2) could be achieved. Furthermore, an excellent stability for 8 times measurements was observed with an RSD of 4.87%, suggesting that the developed tool is promising for the real detection of isoprocarb. |
| ESTHER : Rachmawati_2023_Anal.Sci__ |
| PubMedSearch : Rachmawati_2023_Anal.Sci__ |
| PubMedID: 36821076 |