Highly Sensitive Homogeneous Electrochemiluminescence Biosensor for Alkaline Phosphatase Detection Based on Click Chemistry-Triggered Branched Hybridization Chain Reaction

Abstract

Alkaline phosphatase (ALP) has been used as a diagnostic index of clinical diseases since its expression level is closely related to many pathological processes. In this work, a highly sensitive electrochemiluminescence (ECL) method for the determination of ALP based on a click chemistry-induced branched hybridization chain reaction (BHCR) for signal amplification and ultrafiltration technology for the separation of homogeneous amplification products is introduced. ALP can release copper ions from a Cu 2+ /PPi complex by hydrolyzing pyrophosphoric acid, which initiates click chemistry in the system. A BHCR amplification is triggered afterward by the long single-stranded DNA (ssDNA) generated by click chemistry, resulting in a threedimensional double-stranded DNA (dsDNA) with a large molecular weight. Based on the characteristic that Ru(phen) 3 2+ can stably insert into the groove of dsDNA, a large amount of Ru(phen) 32+ is retained together with the amplified product after ultrafiltration, and therefore a significantly enhanced ECL signal can be obtained. The test results show that this method can be used for the quantitative determination of ALP ranging from 0.002 to 50 U/L, with a detection limit of 0.7 mU/L. This method has also been confirmed to have good selectivity and anti-interference, and the results of the analysis of the ALP content in the diluted serum samples are satisfactory, showing great application potential in clinical diagnosis.

Design of an electrochemiluminescence detection system through the regulation of charge density in a microchannel

“…A tris(1,10-phenanthroline)ruthenium( ii ) (Ru(phen) 3 2+ )/tripropylamine (TPrA) system was used in our previous work. 34 It possessed similar performance to the commonly used tris(2,2′-bipyridine)ruthenium( ii ) Ru(bpy) 3 2+ /TPrA and Ru(bpy) 3 2+ /2-(dibutylamino)ethanol system 35,36 and therefore was adopted as the model ECL reporting system in the current work. A glassy carbon electrode (GCE) and a platinum (Pt) electrode acted as the driving electrodes and were linked to a microchannel.…”

Strategies for Enhancing the Sensitivity of Electrochemiluminescence Biosensors

“…Therefore, BHCR not only inherits the properties of the nonenzymatic and isothermal amplification characteristics of HCR. However, it also possesses the advantages of rapid reaction kinetics and a high amplification efficiency because of its unique multiple reaction orientations [ 60 ].…”

“… Example of the ECL biosensor for ALP detection based on BHCR amplification. Reproduced with permission from [ 60 ]. Copyright 2021, American Chemical Society.…”

Electrochemistry/Photoelectrochemistry-Based Immunosensing and Aptasensing of Carcinoembryonic Antigen

“…Nucleic acid-based amplification technologies, such as strand displacement reaction (SDR) [63][64][65], metal ion-dependent DNAzyme [66,67], hybridization chain reaction (HCR) [68][69][70], and nuclease cycling cleavage [71,72] remarkably enhanced the detection sensitivity. Zhao et al designed an ultrasensitive impedimetric CEA aptasensor based on the amplification effect of Zn 2+ -dependent DNAzyme-inspired cycling cleavage [73].…”

“…(HCR) [68][69][70], and nuclease cycling cleavage [71,72] remarkably enhanced the detection sensitivity. Zhao et al designed an ultrasensitive impedimetric CEA aptasensor based on the amplification effect of Zn 2+ -dependent DNAzyme-inspired cycling cleavage [73].…”