Sensitive Electrochemiluminescence Biosensor Based on the Target Trigger Difference of the Electrostatic Interaction between an ECL Reporter and the Electrode Surface

Abstract

The discrepancy of the electrostatic interaction of negatively charged signal molecules to long and short DNA strands of the modified electrode surface has been used for the first time to the develop an electrochemiluminescence (ECL) biosensor for human papillomavirus 16 (HPV 16) DNA detection. The short single-stranded capture probe (CP) was modified first on the surface of the gold electrode, which only has a small amount of negative charge. The electrostatic interaction between the negatively charged tris­(2,2′-bipyridyl) ruthenium­(II) chloride hexahydrate-doped SiO2 nanoparticles (Ru@SiO2 NPs) and CP is weak, hence Ru@SiO2 NPs easily diffuse to the surface of the electrode to generate a strong ECL signal. Hybrid chain reaction (HCR) amplification products (long strand dsDNA) were prepared in homogeneous solution in advance. When the target was present, the dsDNA can be connected on the electrode surface and cause the enhancement of the negative charge on the electrode surface. Owing to electrostatic interaction and steric hindrance, Ru@SiO2 NPs are difficult to diffuse to the electrode surface, resulting in a significantly reduced ECL signal. The decrease of ECL signal is linearly correlated with the logarithm of the HPV concentration under optimal conditions, with the detection range being 0.1 fM −5 pM with a limit of 1.41 aM. This innovative methodology expands the application of electrostatic interaction in ECL sensing, but can also easily develop biosensors for detecting other targets by changing the DNA sequence used in this strategy.

High-Density N-Vacancy-Induced Multipath Electrochemiluminescence Improvement of 3D g-C3N4 for Ultrasensitive MiRNA-222 Analysis

“…As some targets could not be directly detected or the targets were extremely low in abundance for detection, the target conversion biosensor had very important research significance. , Realizing effective target amplification in solution and reducing the background signal on the electrode were two key aspects for improving the sensitivity of target conversion biosensor. Various DNA amplification techniques were widely used in the target conversion and signal amplification in solution, such as rolling circle amplification (RCA), catalytic hairpin assembly (CHA), and hybridization chain reaction (HCR). , Among them, HCR had good application prospects due to its advantages of simple operation and being enzyme-free. , However, traditional HCR reaction efficiency is not sufficiently high enough because its kinetics depend on the diffusion of random collisions and interactions of DNA reactants in a homogeneous environment, which needs to be improved urgently. − Fixing the DNA involved in the reaction on a long DNA chain in an ordered manner to assemble comblike DNA nanostructures may enable the HCR reaction to reduce the diffusion process and hybridize more orderly to increase the reaction efficiency. Meanwhile, the background signal of the electrode was also the key to affecting the sensitivity of this kind of biosensor.…”

Electrical Nanobiosensors for Nucleic Acid Based Diagnostics

“…Due to electrostatic interactions and spatial potential resistance effects, Ru@SiO 2 NP was difficult to diffuse onto the electrode surface, resulting in a significant reduction of the ECL signal (Figure 3d). 72 This innovative approach extends the application of electrostatic interactions in ECL sensing. Generally speaking, photoelectric enhanced platform has an expecting prospect in the detection of nucleic acid as a novel discipline developed in recent years.…”

“…When the target is present, dsDNA can be attached to the electrode surface, leading to an enhanced negative charge on the electrode surface. Due to electrostatic interactions and spatial potential resistance effects, Ru@SiO 2 NP was difficult to diffuse onto the electrode surface, resulting in a significant reduction of the ECL signal (Figure d) . This innovative approach extends the application of electrostatic interactions in ECL sensing.…”

“…(d) ECL-based method for the detection of HPV 16. Reproduced from ref . Copyright 2022 American Chemical Society.…”

Recent advances in DNA-based electrogenerated chemiluminescence biosensors

“…In contrast, homogeneous ECL biosensors based on sequence length differences are simple and reproducible by using electrostatic interaction between the DNA strand length variation and the electrode surface to achieve ECL signal changes. Lu et al 104 Please do not adjust margins Please do not adjust margins (Ru@SiO 2 NPs) for the highly sensitive detection of human papillomavirus 16 (HPV16) (Figure 8B). The strength of the ECL signal was varied by the electrostatic interaction between the negative charge carried by Ru@SiO 2 NPs and the negatively charged electrode surface, which enabled the detection of the target HPV concentration by using long and short strand DNA.…”