Ligating Dopamine as Signal Trigger onto the Substrate via Metal-Catalyst-Free Click Chemistry for “Signal-On” Photoelectrochemical Sensing of Ultralow MicroRNA Levels

Abstract

The efficiency of photon-to-electron conversion is extremely restricted by the electron-hole recombinant. Here, a new photoelectrochemical (PEC) sensing platform has been established based on the signal amplification of click chemistry (CC) via hybridization chain reaction (HCR) for highly sensitive microRNA (miRNA) assay. In this proposal, a preferred electron donor dopamine (DA) was first assembled with designed ligation probe (probe-N) via amidation reaction to achieve DA-coordinated signal probe (P-N). The P-N served as a flexible trigger to signal amplification through efficiently suppressing the electron-hole recombinant. Specifically, the P-N can be successfully ligated into the trapped hairpins (H1 and H2) via the superior ligation method of metal-catalyst-free CC, in which the electron donor DA was introduced into the assay system. Moreover, the enzyme-free HCR, employed as a versatile amplification way, ensures that lots of P-N can be attached to the substrate. This PEC sensing for miRNA-141 detection illustrated the outstanding linear response to a concentration variation from 0.1 fM to 0.5 nM and a detection limit down to 27 aM, without additional electron donors. The sensor is further employed to monitor miRNA-141 from prostate carcinoma cell (22Rv1), showing good quantitative detection capability. This strategy exquisitely influences the analytical performance and offers a new PEC route to highly selective and sensitive detection of biological molecules.

Ti3C2 MXene-based Schottky photocathode for enhanced photoelectrochemical sensing

“…Photoelectrochemical (PEC) sensing has been a rapidly evolving analytical technique for trace or ultratrace detection towards diverse biomolecular in complex samples, since the technique is of considerate merits of low background signal, high sensitivity, and simple operating conditions [1][2][3]. Potential photoelectrode candidates should possess highly valid light harvesting, suitable analytes interfacing, efficient PEC signal response, and stable signal transduction to exploit ideal PEC sensing platform [4][5][6]. Up to now, plentiful efforts are focused on developing photoactive materials to obtain desirable photoelectrode, such as TiO 2 -based or quantum dots-based nanomaterials, as well as porphyrin and its derivatives [7,8].…”

Semiconducting Organic–Inorganic Nanodots Heterojunctions: Platforms for General Photoelectrochemical Bioanalysis Application

“…In the quest for achieving better performance, heterojunctions consisting of two semiconductors are being looked upon as favorite schemes because appropriate alignment of particular semiconductors may produce novel photoelectrodes with fascinating characteristics. To this end, our group and other groups have developed many hierarchical heterostructures for PEC bioanalysis applications. − For example, p-n heterojunction of BiOI nanoflakes/TiO 2 nanotubes and p-p heterojunction of PdS Qdots/NiO nanofilm have been developed for PEC immunoassay and PEC enzymatic sensing, respectively. However, these hybrids were generally composed of various inorganic semiconductors.…”

Highly effective molecule converting strategy based on enzyme-free dual recycling amplification for ultrasensitive electrochemical detection of ATP

“…The CHI 660D electrochemical workstation (Shanghai Chen Hua Instrument, China) was used for all electrochemical measurements including electrochemical impedance spectroscopy (EIS), square wave voltammetry (SWV) and cyclic voltammetry (CV). The traditional three-electrode consisted of glassy carbon electrode (GCE, Φ = 4 mm) as working electrode, a saturated calomel reference electrode (SCE) and a platinum wire auxiliary electrode [3] . The pH meter (MP 230, Mettler Toledo, Switzerland) was utilized to perform pH measurements.…”