A triboelectric nanosensor based on ultra-thin MXene composite paper for heavy metal ion detection

Abstract Heavy metal pollution has become increasingly serious in recent decades with the progress of industrialization, posing a significant threat to human health. This raises the demand for portable and ease of use heavy metal ion detection devices. In this study, we develop ultra-thin (5 µ m) and highly flexible composite paper of MXene/bacterial cellulose (M/BC x , with x denoting the BC content) and apply it in a self-powered triboelectric nanosensor (TENS) to do heavy metal ion detection. The M/BC x composite paper is fabricated using a simple vacuum filtration method, and combines the advantages of the high electrical conductivity of MXene with the excellent mechanical properties of BC. The TENS employs the M/BC x composite paper and polytetrafluoroethylene as the friction layers, and the influences of different ratios of M/BC x on the electrical signals is investigated. The TENS shows high sensitivity in the detection of Cu 2+ , Cr 3+ , and Zn 2+ , as the detection limit is as low as 1 µ M without the need of ligand molecules. A linear range of 10–300 µ M is obtained. The TENS also shows excellent stability after more than 10 000 continuous operations. This simple-structured, cost-effective and durable TENS device provides new insights into the methodology of heavy metal ion detection and can be further developed for the detection of the corresponding ions in serum.