Facile synthesis of biomass waste-derived fluorescent N, S, P co-doped carbon dots for detection of Fe3+ ions in solutions and living cells

Abstract

Fluorescent carbon dots derived from natural biomass have received widespread attention in recent years due to their superior optical and chemical properties. In this work, we proposed a method to synthesize fluorescent nitrogen, sulfur, and phosphorus co-doped carbon dots (NSP-CDs) using biomass waste as a precursor. The blue emitting carbon dots were prepared from the seeds of green pepper, and Fe³⁺ ions could quench the fluorescence of NSP-CDs. Therefore, a fluorescent “turn-off” sensor based on NSP-CDs was constructed for the detection of Fe³⁺ ions. Further, NSP-CDs were evaluated as a fluorescent biosensor for the detection of Fe³⁺ in tap water and lake water samples, showing their potential value in practical applications. The cytotoxicity test further confirmed that NSP-CDs have good biocompatibility and can be extended to cell imaging and intracellular Fe³⁺ detection. The proposed method is simple, economical and green, which can meet the requirements of environmental monitoring and biological imaging.