Laccase-Prussian blue film-graphene doped carbon paste modified electrode for carbamate pesticides quantification

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Thiago M B F Oliveira (Author) Other; Fatima Barroso, MF (Author) Other; Simone Morais (Author) Other; Mariana Araujo (Author) Other; Cristina Freire (Author) FCUP; Pedro de Lima Neto (Author) Other; Adriana N Correia (Author) Other; Maria B P P Oliveira (Author) FFUP; Cristina Delerue Matos (Author) Other

Journal

Title: Biosensors and Bioelectronics

Vol. 47

Pages: 292-299

ISSN: 0956-5663

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 44 Citations

Scopus - 50 Citations

Scientific classification

FOS: Engineering and technology > Nano-technology

Other information

Authenticus ID: P-004-ZP9

DOI: 10.1016/j.bios.2013.03.026

Abstract (EN): A novel enzymatic biosensor for carbamate pesticides detection was developed through the direct immobilization of Trametes versicolor laccase on graphene doped carbon paste electrode functionalized with Prussian blue films (LACC/PB/GPE). Graphene was prepared by graphite sonication-assisted exfoliation and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The Prussian blue film electrodeposited onto graphene doped carbon paste electrode allowed considerable reduction of the charge transfer resistance and of the capacitance of the device. The combined effects of pH, enzyme concentration and incubation time on biosensor response were optimized using a 2(3) full-factorial statistical design and response surface methodology. Based on the inhibition of laccase activity and using 4-aminophenol as redox mediator at pH 5.0, LACC/PB/GPE exhibited suitable characteristics in terms of sensitivity, intra- and inter-day repeatability (1.8-3.8% RSD), reproducibility (4.1 and 6.3% RSD), selectivity (13.2% bias at the higher interference:substrate ratios tested), accuracy and stability (ca. twenty days) for quantification of five carbamates widely applied on tomato and potato crops. The attained detection limits ranged between 5.2 x 10(-9) mol L-1 (0.002 mg kg(-1) w/w for ziram) and 1.0 x 10(-7) mol L-1 (0.022 mg kg(-1) w/w for carbofuran). Recovery values for the two tested spiking levels ranged from 90.2 +/- 0.1 (carbofuran) to 101.1 +/- 0.3% (ziram) for tomato and from 91.0 +/- 0.1% (formetanate) to 100.8 +/- 0.1% (ziram) for potato samples. The proposed methodology is appropriate to enable testing pesticide levels in food samples to fit with regulations and food inspections.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8