Electrochemiluminescent determination of prostate-specific antigen using Au@(MoS2/GO/o-MWNTs) nanohybrids as co-reaction accelerator and hyperbranched hybridization chain reaction for signal amplification

An enzyme-free multi-stage hybridization chain reaction for the electrochemiluminescence detection of MRSA using MoS2 NF@AuNPs catalyst

Methicillin-resistant Staphylococcus aureus (MRSA) is a ubiquitous foodborne pathogen capable of causing food poisoning and producing enterotoxins in foodstuffs, which ultimately results in various illnesses, such as vomiting, diarrhea, and pneumonia. In this study, we present a MoS2 NF@AuNPs enhanced electrochemiluminescence (ECL) biosensor for MRSA detection based on a DNA branching tree structure formed via enzyme-free hybridization chain reaction (HCR) amplification. This approach integrates bacterial aptamers with multistage HCR amplification to achieve highly sensitive and specific target recognition. Furthermore, MoS2 NF@AuNPs act as a synergistic catalyst for Ru(bpy)32+ molecules, which in turn substantially enhances the signal readout of the biosensor. The biosensor exhibits a robust linear correlation for MRSA detection over a concentration range of 100 to 107 cfu/mL, with a detection limit of 1 cfu/mL. In addition, the biosensor demonstrates excellent selectivity and high sensitivity when applied to real samples such as water, juice, and milk.

Traditional and new applications of the HCR in biosensing and biomedicine

The hybridization chain reaction is a very popular isothermal nucleic acid amplification technology. A single-stranded DNA initiator triggers an alternate hybridization event between two hairpins forming a double helix polymer. Due to isothermal, enzyme-free and high amplification efficiency characteristics, the HCR is often used as a signal amplification technology for various biosensing and biomedicine fields. However, as an enzyme-free self-assembly reaction, it has some inevitable shortcomings of relatively slow kinetics, low cell internalization efficiency, weak biostability of DNA probes and uncontrollable reaction in these applications. More and more researchers use this reaction system to synthesize new materials. New materials can avoid these problems skillfully by virtue of their inherent biological characteristics, molecular recognition ability, sequence programmability and biocompatibility. Here, we summarized the traditional application of the HCR in biosensing and biomedicine in recent years, and also introduced its new application in the synthesis of new materials for biosensing and biomedicine. Finally, we summarized the development and challenges of the HCR in biosensing and biomedicine in recent years. We hope to give readers some enlightenment and help.