Electrochemical Biosensor Based on Dual-Ligand Functionalized Lanthanide-Encapsulated Polyoxometalate Conductive Polymer Film for Detecting Broad-Spectrum Tumor Marker MicroRNA-155

Abstract

In this work, a dual-ligand functionalized lanthan i d e -e n c a p s u l a t e d s e l e n o t u n g s t a t e [ H 2 N -(CH 3 ) 2 ] 16 Na 2 H 10 [Ho 6 (H 2 O) 10 (HPACA) 4 W 10 O 28 (Ac) 2 ]-[SeW 9 O 33 ] 6 • 60H 2 O (1, HPACA = 2-pyrazinecarboxylic acid, HAc = acetic acid) was successfully acquired by simultaneously incorporating rigid HPACA and flexible Ac − ligands to one r e a c t i o n s y s t e m . I n t e r e s t i n g l y , t h e p o l y a n i o n [Ho 6units interconnected through an organic−inorganic hybrid dual-ligand bimetallic [Ho 6 (H 2 O) 10 (HPACA) 4 W 10 O 28 (Ac) 2 ] 20+ cluster. Moreover, the 1@PNMPy film (PNMPy = poly(N-methylpyrrole)) was successfully prepared through an electrochemical polymerization strategy. The doping of 1 significantly narrows the bandgap in the 1@PNMPy film, which enables the 1@PNMPy film to exhibit remarkable conductivity and rapid electron transfer capability. Then, the 1@PNMPy film-modified glassy carbon electrode was used to construct a 1@PNMPy-based electrochemical biosensor (ECBS), which achieves sensitive electrochemical detection (a low limit of detection of 0.108 fM and a wide concentration detection range of 10 −8 −10 −15 M) for broad-spectrum tumor marker microRNA-155. Also, the 1@PNMPy-based ECBS has a good specific recognition performance for microRNA-155 in a variety of interfering media. The research not only contributes to a deeper understanding of the synthetic chemistry of multicomponent polyoxometalate (POM)-based materials but also can further expand innovative applications of multicomponent POM-based materials in electrochemical detection and electrochemical devices.