A self-enhanced renewable electrochemiluminescence biosensing platform for ultrasensitive detection of sialic acid

Abstract

Herein, a boronate-affinity renewable electrochemiluminescence (ECL) biosensor was constructed based on a highly efficient Ru (II)-based composite for the sensitive detection of sialic acid (SA). Specifically, the Bi nanobelts (Bi NBs) was first used as coreactant to prepare a self-enhanced Ru(bpy)32+-Bi NBs composite, producing a strong ECL signal by shortening electronic transmission distance and reducing the energy loss. Additionally, HNO3-assisted synthesized rutile TiO2 mesocrystals (Nss-TiO2-RM) with nanoporous nature and single-crystal like structure was employed as scaffold, increasing the immobilization amount of Ru(bpy)32+ and Bi NBs, further enhancing ECL signal. Promisingly, 4-Mercaptophenylboronic acid (4-MPBA) as bionic recognition unit could substitute antibody to capture SA, and moreover a self-cleaning electrode could be obtained after treated by 0.1 M PBS (pH 6). Under optimal conditions, a sandwich-like renewable ECL biosensor was constructed for sensitive detection of SA in the range of 3.5 × 10−5 to 350 ng/mL with a low detection limit of 1.17 × 10−5 ng/mL. This work provided a new thought for other biomarkers determination.