Label-free and sensitive electrochemiluminescent immunosensor based on novel luminophores of Zn2SnO4 nanorods

Abstract Zinc stannate (Zn2SnO4) nanorods with promising biocompatibility, low toxicity, was firstly observed to show excellent cathodic electrochemiluminescence (ECL) emission and used as a brand-new ECL luminophore to fabricate a sensitive and novel label-free immunosensor in this paper. Zn2SnO4 nanorods were synthesized via a simple hydrothermal technique and consequent heat treatment. After amino-functionalization with 3-aminopropyltriethoxysilane (APTES), the Zn2SnO4-NH2 was acquired, which was functionalize with gold nanoparticles (Au NPs) via Au-N linkage (Au@Zn2SnO4) wherein Au NPs could immobilized large amount of α-fetoprotein (AFP) antibodies and can also heightened the ECL emission of Zn2SnO4. In order to corroborate the viability of designed immunosensor, AFP antigen was employed as an exemplary analyte. Tests relating to AFP detection revealed that our immunosensor presented high sensitivity, wide detection range ((0.001 ng - 50 ng/mL), low limit of detection (3.4 pg/mL, S/N = 3), good specificity, reproducibility, and long-term stability. Furthermore, the trustworthiness of the acquired ECL immunosensor has been attested through AFP detection in real human serum samples with adequate outcomes.