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Label-free electrochemical aptasensor for the detection of lysozyme

2008; Elsevier BV; Volume: 78; Issue: 1 Linguagem: Inglês

10.1016/j.talanta.2008.11.002

1873-3573

Maria Carmen Rodríguez, Gustavo A. Rivas,

Electrochemical Analysis and Applications

This work reports the advantages of a label free electrochemical aptasensor for the detection of lysozyme. The biorecognition platform was obtained by the adsorption of the aptamer on the surface of a carbon paste electrode (CPE) previously blocked with mouse immunoglobulin under controlled-potential conditions. The recognition event was detected from the decrease in the guanine and adenine electro-oxidation signals produced as a consequence of the molecular interaction between the aptamer and lysozyme. The biosensing platform demonstrated to be highly selective even in the presence of large excess (9-fold) of bovine serum albumin, cytochrome C and myoglobin. The reproducibility for 10 repetitive determinations of 10.0 mg L−1 lysozyme solution was 5.1% and 6.8% for guanine and adenine electro-oxidation signals, respectively. The detection limits of the aptasensor were 36.0 nmol L−1 (if considering guanine signal) and 18.0 nmol L−1 (if taking adenine oxidation current). This new sensing approach represents an interesting and promising alternative for the electrochemical quantification of lysozyme.