1：Experimental Design and Method Selection:

The study involved designing and synthesizing a sensor (3TI) based on oligothiophene-indenedione for detecting cyanide anions through nucleophilic addition, which inhibits intramolecular charge transfer (ICT). Methods included UV-Vis and fluorescence spectroscopy, NMR titration, FTIR, HRMS, and TD-DFT calculations.

2：Sample Selection and Data Sources:

Samples included synthetic sensor 3TI, various anions (e.g., CN?, F?, Cl?) from commercial sources, real water samples (tap, distilled, lake water), food samples (cassava, bitter seeds, etc.), and HeLa cells for bioimaging.

3：List of Experimental Equipment and Materials:

Equipment included Bruker Avance II NMR spectrometer, Bruker ALPHA FT-IR spectrometer, Agilent 6510 Accurate-Mass Q-TOF LC/MS, Shimadzu UV-2600 spectrophotometer, Hitachi F-4600 fluorescence spectrophotometer, Leica TCS SP8 confocal-laser scanning microscope, PHS-3C pH meter, and Multiskan FC Microplate Photometer. Materials included chemical reagents, solvents, tetrabutylammonium salts of anions, silica gel, and cell culture media.

4：Experimental Procedures and Operational Workflow:

Synthesis of 3TI via condensation reaction; optical response tests with anions; cytotoxicity assay using MTT method; cell culture and fluorescence imaging with HeLa cells; practical applications in water and food samples and silica-based kits.

5：Data Analysis Methods:

Data were analyzed using UV-Vis and fluorescence spectra, NMR and FTIR spectra for mechanism confirmation, HRMS for mass analysis, TD-DFT calculations for electronic structure, and statistical methods for detection limit and recovery calculations.