Label-free electrochemical aptasensor for the detection of lysozyme

MARCELA C. RODRÍGUEZ; GUSTAVO A. RIVAS

TALANTA

ELSEVIER SCIENCE BV

Año: 2009 vol. 78 p. 212 - 216

0039-9140

 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.