A multifunctional fluorescent probe for simultaneous detection of SO2/SO32−, FA, and ClO− and its applications in encryption ink and bioimaging

Abstract

Sulfur dioxide (SO₂), formaldehyde (FA), and hypochlorite (ClO⁻) are highly reactive chemical species that are commonly encountered in both daily life and industrial applications. Excessive exposure to these substances can pose significant risks to the environment, ecosystems, and human health. Therefore, the development of methods for the efficient, sensitive, and convenient simultaneous detection of SO₂/SO₃²⁻, FA, and ClO⁻ has become a key area of research. In this study, we designed a multifunctional fluorescent probe (YPTZ) with three distinct responsive sites, enabling it to simultaneously detect SO₂/SO₃²⁻, FA, and ClO⁻. The limits of detection (LODs) of YPTZ for SO₂/SO₃²⁻ and FA were determined to be 0.20 μM (0.1–30 μM) and 0.22 μM (0.1–24 μM), respectively, while the LODs for ClO⁻ were 6.2 nM (0.1–5 μM) and 0.03 μM (5–24 μM). YPTZ exhibited excellent selectivity and strong anti-interference capabilities. YPTZ-loaded test strips were successfully fabricated and combined with smartphones to enable portable and intelligent detection of these three substances. Furthermore, YPTZ was applied to the detection of SO₂/SO₃²⁻, FA, and ClO⁻ in actual water samples, yielding satisfactory results with recoveries ranging from 96.74% to 108.77%. Additionally, the reversible detection of SO₂/SO₃²⁻ and FA by YPTZ was utilized to develop an encryption ink. YPTZ was also successfully used for imaging ClO⁻ in living cells. The multifunctional probe YPTZ is a powerful visual tool for simultaneous detection and identification of SO₂/SO₃²⁻, FA, and ClO⁻, with potential applications in environmental monitoring, security, and bioimaging.