High-selectivity NIR biosensor and in vivo imaging for Hg2+ detection based on a DNA-wrapped single-chirality carbon nanotube

Lele Wang; Han Liu; Lanying Li; Ruiyan Guo; Xuefei Yang; Xiaoqian Chen; Yanli Wen; Meixia Cao; Juan Yan; Gang Liu

doi:10.1016/j.jhazmat.2025.138979

High-selectivity NIR biosensor and in vivo imaging for Hg²⁺ detection based on a DNA-wrapped single-chirality carbon nanotube

J Hazard Mater. 2025 Jun 18:495:138979. doi: 10.1016/j.jhazmat.2025.138979. Online ahead of print.

Authors

Lele Wang¹, Han Liu², Lanying Li¹, Ruiyan Guo¹, Xuefei Yang³, Xiaoqian Chen³, Yanli Wen¹, Meixia Cao¹, Juan Yan⁴, Gang Liu⁵

Affiliations

¹ Key Laboratory of Bioanalysis and Metrology for State Market Regulation, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China.
² Key Laboratory of Bioanalysis and Metrology for State Market Regulation, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China; International Research Center for Food and Health, College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
³ Bioassay and Assessment Laboratory, Shanghai Academy of Public Measurement, Shanghai 201203, China.
⁴ International Research Center for Food and Health, College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
⁵ Key Laboratory of Bioanalysis and Metrology for State Market Regulation, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China. Electronic address: liug@simt.com.cn.

PMID: 40543343
DOI: 10.1016/j.jhazmat.2025.138979

Abstract

The development of nano-probes for mercury ion (Hg²⁺) detection has attracted increasing attention owing to their high sensitivity and biocompatibility, yet critical challenges persist in material purity, structural stability, and practical applicability across diverse matrices. Single-chirality carbon nanotubes (CNTs) exhibit unique advantages in near-infrared (NIR 780 nm to 2500 nm) fluorescence sensing, but their functionalization strategies and environmental monitoring applications remain underexplored. Herein, we constructed a NIR biosensor probe using a high-purity (96 %) monochiral CNT (8, 4), wrapped with a designed thymine-rich DNA on (8, 4) surface, forming a spiral structure. Due to the affinity and interaction between T-Hg²⁺, the spiral structure of DNA-CNT was affected, thereby altering its fluorescence emission. The DNA-CNT Hg²⁺ NIR biosensor achieved a detection limit of 0.472 nM (S/N = 3) with linearity from 0.8 nM to 40 nM. Remarkably, the biosensor demonstrated excellent selectivity against 10 metal ions and practicability in real samples. It reliably quantified Hg²⁺ in complex river water samples (recovery: 93.9 %-108.7 %) and enabled real-time in vivo imaging in zebrafish models. The modular design further allowed versatile target switching by simply replacing surface DNA probes, thereby establishing a multifunctional biosensing platform. This work not only addresses purity and stability bottlenecks but also establishes a modular framework for constructing single-chirality CNT-based NIR probes, demonstrating their validated application in environmental mercury detection.

Keywords: DNA; Hg(2+); NIR biosensor; Single-chirality CNT.