An organic-phase optical phenol biosensor coupling enzymatic oxidation with chemical reduction.
This paper presents a recycle amplification optical biosensor to monitor phenol in hydrophobic organic solvents. Tyrosinase was first immobilised by entrapping it in a copolymer membrane of poly(vinyl alcohol)-hydroxyethyl carboxymethylcellulose doped with octadecylsilica particles. The biosensor was then constructed by co-mixing small particles of the immobilised tyrosinase with the adduct of L-ascorbic acid-poly(vinyl alcohol) (AsA-PVA) in conjunction with an optical oxygen transducer. The biosensor was characterised by its amplifying response to phenol, stable biocatalytic activity of entrapped-tyrosinase, free of interference from o-quinone polymerisation, and large water buffer capacity in hydrophobic organic solvents. The working range of the biosensor to phenol was 0.08-40 mmol dm(-3) in the flow mode. The response times (95%) of the biosensor were 4-7 min for phenol. The operational lifetime was more than 40 assays and the shelf lifetime of the biosensor was longer than 3 months. The biosensor has been successfully applied to quantify the phenol contents in some commercial ointment samples.
Wu
Xiao Jun
XJ
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, P. R. China.
Choi
Martin M F
MM
Wu
Xiao Min
XM
D015374:Biosensing Techniques / Q000379:methods*; D009824:Ointments / Q000737:chemistry; D010084:Oxidation-Reduction; D019800:Phenol / Q000032:analysis*; D012997:Solvents; D014867:Water
D009824:Ointments; D012997:Solvents; D014867:Water; D019800:Phenol