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

• Published in: RSC advances 2024-03, Vol.14 (13), p.8885-8895
• Main Authors: Ilakiyalakshmi, Mohan, Napoleon, Ayyakannu Arumugam
• Format: Article
• Language: English
• Subjects: Acetonitrile; Aqueous solutions; Biocompatibility; Cations; Cells (biology); Chemistry; Copper; Density functional theory; Doppler effect; Fluorescent indicators; In vivo methods and tests; Mathematical analysis; NMR; Nuclear magnetic resonance; Red shift; Visual observation; Water sampling
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d3ra07608c

This research paper unveils a fluorescent probe ( PTZ-SCN ) engineered for the specific detection of Cu 2+ , featuring a 10-ethyl-10 H -phenothiazine-3-carbaldehyde and 2-(thiophen-2-yl) acetonitrile moiety. The fluorescence sensing behavior of PTZ-SCN towards various metal cations was scrutinized in CH 3 CN : HEPES (9 : 1) buffer aqueous solution. The UV absorbance of PTZ-SCN displayed a distinct red shift in the presence of Cu 2+ cations, whereas other metal cations did not cause any interference. Similarly, the fluorescence emission of the probe was also only quenched by Cu 2+ cations. The limit of detection (LOD) was calculated as 1.0461 × 10 −8 M. PTZ-SCN showed the ability to identify Cu 2+ 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 2+ using 1 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 2+ . Additionally, the PTZ-SCN probe's low cytotoxicity and effective imaging properties for Cu 2+ in living cells were confirmed, indicating that PTZ-SCN shows the potential to serve as a promising probe for detecting Cu 2+ in vivo . A novel phenothiazine-thiophene acetonitrile compound was synthesised through a Knoevenagel condensation reaction. The compound demonstrated selectivity towards Cu 2+ and proved to have low cytotoxicity.