Respective and simultaneous detection tumor markers CA125 and STIP1 using aptamer-based fluorescent and RLS sensors

Abstract

Here we reported a method for the early diagnosis of ovarian cancer that is respective and simultaneous detection of tumour marker cancer antigen 125 (CA125) and stress-induced phosphoprotein 1 (STIP1) using aptamer-based fluorescent and RLS sensors. The fluorescent sensor was fabricated by Carboxyfluorescein (FAM)-labelled CA125 aptamer and cyanine-5-modified STIP1 aptamer onto the surface of RGO, thereby quenching the fluorescence of fluorophores. When STIP1 was introduced, the fluorescence recovered. When CA125 was added, the specific binding of aptamer and CA125 triggered the release of the FAM-labeled CA125 aptamer under the effect of formaldehyde, and adsorbed on the surface of RGO which lead to fluorescence quenching of FAM. This fluorescence signals change could be used to detect CA125 and STIP1 with the lowest detectable concentration down to 0.05UmL−1 and 1ngmL−1 respectively. The RLS sensor was fabricated by methyl violet interact with dsDNA which is obtained by CA125 aptamer hybridized to STIP1 aptamer. The dependence of RLS intensity on targets amount was successfully utilized for simultaneous detection of CA125 and STIP1, which provide robust evidences for the presence of ovarian cancer in the early stage. This strategy is reliable, sensitive, and may form the basis for rapid screening of ovarian cancer.