All-in-one strategy for the nano-engineering of paper-based bifunctional fluorescent platform for robustly-integrated real-time monitoring of food and drinking-water safety

Abstract

Cu²⁺ contamination and food spoilage raise food and drinking water safety issues, posing a serious threat to human health. Besides, Cu²⁺ and H₂S levels indicate excess Cu²⁺-caused diseases and protein-containing food spoilage. Herein, a coumarin-containing bifunctional paper-based fluorescent platform integrated with a straightforward smartphone color recognition app is developed by an all-in-one strategy. The proposed fluorescent materials can simultaneously detect Cu²⁺ and H₂S for on-demand food and drinking water safety monitoring at home. Specifically, a coumarin-derived fluorescence sensor (referred to as CMIA) with a low detection limit (0.430 μM) and high-selectivity/-sensitivity for Cu²⁺ is synthesized through a simple one-step route and then loaded onto commercially used cellulose fiber filter paper to engineer a biomass-based fluorescent material (CMIA-FP). The CMIA-FP offers user-friendly, high-precision, fast-responsive, and real-time visual monitoring of Cu²⁺. Moreover, CMIA forms a chemically stable complex with Cu²⁺, loaded onto filter paper to prepare another biomass-based fluorescent platform (CMIA-CU-FP) for visual real-time monitoring of H₂S. Based on the exquisite composition design, the proposed dual-function paper-based fluorescent materials equipped with a smartphone color recognition program concurrently realize fast, accurate, and easy real-time monitoring of Cu²⁺ in drinking water and H₂S in chicken breast-/shrimp-spoilage, demonstrating an effective detection strategy for the Cu²⁺ and H₂S monitoring and presenting the new type of biomass-based platforms for concentrated reflection of drinking water and food safety.

Keywords: Bifunctional probe; Cu(2+)/H(2)S; Food spoilage and drinking water safety; Paper; Visual monitoring.