Phenothiazine appended thiophene derivative: a trilateral approach to copper ion detection in living cells and aqueous samples.

This research paper unveils a fluorescent probe (PTZ-SCN) engineered for the specific detection of Cu, featuring a 10-ethyl-10-phenothiazine-3-carbaldehyde and 2-(thiophen-2-yl) acetonitrile moiety. The fluorescence sensing behavior of PTZ-SCN towards various metal cations was scrutinized in CHCN : HEPES (9 : 1) buffer aqueous solution. The UV absorbance of PTZ-SCN displayed a distinct red shift in the presence of Cu cations, whereas other metal cations did not cause any interference. Similarly, the fluorescence emission of the probe was also only quenched by Cu cations. The limit of detection (LOD) was calculated as 1.0461 × 10 M. PTZ-SCN showed the ability to identify Cu using the colorimetric method, the fluorometric method and even through visual observation in a trilateral detection. We studied the recognition mechanism of PTZ-SCN for Cu using H-NMR, HRMS analysis, and time-dependent density functional theory (TDDFT) calculations. Furthermore, our study encompassed the investigation of PTZ-SCN's practical applicability, bridging the gap from research to real-world implementation. This was achieved by employing test strips and water samples for the detection of Cu. Additionally, the PTZ-SCN probe's low cytotoxicity and effective imaging properties for Cu in living cells were confirmed, indicating that PTZ-SCN shows the potential to serve as a promising probe for detecting Cu.