Dhandapani Vinayagam, Karpagam Subramanian
Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore -14, Tamil Nadu, India.
J Fluoresc. 2025 Jan 10. doi: 10.1007/s10895-024-04110-z.
This study addresses the critical issue of irreversible oxidation in hypochlorite (ClO⁻) sensing by a phenothiazine-based compound, which typically leads to the probe's degradation and loss of functionality. We introduce a novel fluorescence probe, (2-(5-(10 H-phenothiazin-10-yl)thiophen-2-yl)-1 H-benzo[d]imidazol-6-yl)(phenyl)methanone (PTH-BP), specifically designed to enhance ClO⁻ detection efficiency. PTH-BP exhibits strong aggregation-induced emission (AIE), emitting deep orange fluorescence at 620 nm with a large Stokes shift of 195 nm, and achieves an impressive detection limit of 1 nM in ACN/PBS buffer solutions. Job's plot analysis reveals a 1:1 binding stoichiometry, while fluorescence quenching occurs due to the oxidation of the phenothiazine sulfur to sulfoxide, confirmed by high-resolution mass spectrometry (HRMS). The probe's design improves stability, enabling effective real-time ClO⁻ monitoring and demonstrating reliable performance in electrochemical sensing. Furthermore, PTH-BP shows excellent imaging capabilities in HeLa cells, characterized by low toxicity and good permeability, making it a strong candidate for environmental, biological, and industrial applications. This breakthrough offers a robust and versatile approach to overcoming limitations in phenothiazine-based ClO⁻ sensing.
本研究解决了基于吩噻嗪的化合物在次氯酸盐（ClO⁻）传感中不可逆氧化这一关键问题，这种氧化通常会导致探针降解并失去功能。我们引入了一种新型荧光探针，即(2-(5-(10H-吩噻嗪-10-基)噻吩-2-基)-1H-苯并[d]咪唑-6-基)(苯基)甲酮（PTH-BP），其专门设计用于提高ClO⁻检测效率。PTH-BP表现出强烈的聚集诱导发光（AIE），在620 nm处发射深橙色荧光，斯托克斯位移达195 nm，在乙腈/磷酸盐缓冲液中检测限低至1 nM。Job曲线分析表明其结合化学计量比为1:1，同时荧光猝灭是由于吩噻嗪硫被氧化为亚砜，高分辨率质谱（HRMS）证实了这一点。该探针的设计提高了稳定性，能够实现有效的实时ClO⁻监测，并在电化学传感中表现出可靠的性能。此外，PTH-BP在HeLa细胞中显示出优异的成像能力，具有低毒性和良好的渗透性，使其成为环境、生物和工业应用的有力候选者。这一突破为克服基于吩噻嗪的ClO⁻传感的局限性提供了一种强大且通用的方法。
