Electrochemical biosensor for detection of formaldehyde in rain water

摘要: BACKGROUD: This study describes the construction of an electrochemical formaldehyde biosensor based on poly(glycidyl methacrylate-co-3-methylthienyl methacrylate)/formaldehyde dehydrogenase/polypyrrole [poly(GMA-co-MTM)/FDH/PPy] composite film electrode. Formaldehyde dehydrogenase (FDH) was chemically immobilized via epoxy groups glycidyl methacrylate (GMA) side chain polymer. measurements were conducted in 0.1 mol L−1, pH 8 phosphate buffer solution (PBS) including L−1 KCl, 0.5 mmol NAD+ (cofactor enzyme) and 1 1,2-napthoquinone-4-sulfonic acid sodium salt (NQS) as mediator with applied potential − 0.23 V (vs. Ag/AgCl, 3 NaCl). Analytical parameters calculated discussed. The tested rain water samples. RESULTS: Sensitivity found to be 15 000 per (500 nA ppm−1) a linear range between ppm (3.3–100 µmol L−1). A minimum detectable concentration 4.5 ppb (0.15 L−1) (S/N = 3) relative standard deviation (RSD) 0.73% (n 5) obtained from biosensor. Response time very short, reaching 99% its maximum response about 4 s. also for samples. concentrations samples using proposed recovery values ranged 92.2 97.7% comparison colorimetric Nash method. CONCLUSION: poly(GMA-co-MTM)/FDH/PPy) electrode showed excellent measurement sensitivity other studies. Strong chemical bonding enzyme copolymer created film. could used successfully waters without pretreatment step. © 2012 Society Chemical Industry