An ellipsometric biosensor using aptamer for the detection of mercuric ions

Abstract

An ellipsometric biosensor, to be used in the detection of mercuric ions that affect the vital organs of living organisms, was developed. In this context, as a diagnostic element of the developed ellipsometric biosensor, a nucleic acid-based aptamer that is highly selective for mercuric ions (Hg2+) was used. Two different aptamers, a long and straight sequence, and a hairpin-structured oligonucleotide sequence were chosen. The detection sensitivity obtained by both aptamers was 0.237 degrees/mu M and 0.211 degrees/mu M, respectively. The detection limit was 0.89 pM Hg2+ and 187 nM Hg2+ for linear- and hairpin-type oligonucleotide, respectively.