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Electrochemical sensor for uric acid based on a molecularly imprinted polymer brush grafted to tetraethoxysilane derived sol-gel thin film graphite electrode

2008; Elsevier BV; Volume: 29; Issue: 5 Linguagem: Inglês

10.1016/j.msec.2008.12.008

1873-0191

Amit Patel, Piyush Sindhu Sharma, Bhim Bali Prasad,

Electrochemical sensors and biosensors

Determination of uric acid in human serum and urine is useful to provide treatment guidelines to hyperuricemic patients. An electrochemical sensor was developed for selective and quantitative recognition of uric acid by using a preanodised sol-gel coated graphite electrode with a molecularly imprinted polymer brush of poly(melamine–co-chloranil) grafted to its exterior surface. During a preconcentration step at (+ 2.0 V versus saturated calomel electrode), the encapsulated analyte recapture involved hydrophobically induced hydrogen-bondings in outwardly exposed MIP cavities in aqueous environment (pH 7.0), instantly oxidised as dications, and then cathodically stripped off as corresponding lactam responding differential pulse, cathodic stripping voltammetric signal. The uric acid was selectively detected without any cross reactivity in the windows of 14.56–177.42 µg mL− 1 (aqueous medium), 4.78–106.96 µg mL− 1 (blood serum), and 7.81–148.42 µg mL− 1 (urine) indicating detection limits in the range of 3.71–4.10 µg mL− 1 (3σ, RSD = 1.9%).