# Single DNA hairpin nanowire based on self-hybridization chain reaction for sensitive ATP detection

## TL;DR

Researchers developed a new DNA-based nanowire that can detect ATP in cells with high sensitivity and selectivity.

## Contribution

A single DNA hairpin structure enables self-hybridization chain reaction, simplifying design and improving detection performance.

## Key findings

- The single hairpin design improves signal-to-noise ratio by nearly two-fold compared to traditional HCR.
- The SHCR nanowire can detect ATP in living cells and ATP released from dead cancer cells after radiotherapy.
- The new design shows better selectivity for single-base mismatches.

## Abstract

Hybridization chain reaction (HCR), which typically consists of two hairpins for signal amplification, has emerged as a versatile tool in bioanalytical applications. Here, a novel HCR nanowire based on a single DNA hairpin structure is reported. The hairpin stem is rationally engineered with a palindromic sequence, which enables a self-hybridization chain reaction (SHCR) upon the introduction of the initiator DNA strand. Compared to the conventional two hairpin-based HCR nanowire, the single DNA hairpin-based SHCR nanowire achieves nearly a two-fold improvement in the signal-to-noise ratio and exhibits better selectivity for single-base mismatch. By integrating the initiator DNA strand with adenosine triphosphate (ATP) aptamer, the single DNA hairpin-based nanowire has been applied for sensitive ATP detection, capable of monitoring ATP both in living cells and that released from dead cancer cells post-radiotherapy. The SHCR nanowire we proposed here has significantly simplified the sequence design of HCR and holds promise as a potential alternative to the conventional HCR nanowire.

This study succeeded in producing single DNA hairpin nanowires based on self-hybridization chain reaction for intracellular ATP monitoring and evaluating the viability of cells in vitro.