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oai:figshare.com:article/34041459 2026-10-01T08:10:37Z category_1 category_4 category_146 category_12 category_19 category_873 category_734 category_61 portal_63 item_type_6 month_year_10_2026

Structure–Driven Intramolecular Charge Transfer Modulation in Imidazole Fluorophores for Selective Hydrazine Detection and Forensic Applications Yu-Hsin Chen (362657) Yu-Hong Chen (45169) Wei-Ting Chien (2091745) Hsin-Chieh Lin (1735546) Mei-Yu Yeh (433818) Biophysics Biochemistry Space Science Cell Biology Pharmacology Chemical Sciences not elsewhere classified Biological Sciences not elsewhere classified Developmental Biology withdrawing dicyanovinyl unit visually discernible signals versatile molecular platform state fluorescent powder offering new opportunities observed optical changes necessitating sensitive detection multilevel fingerprint features mechanistic investigations using mass spectrometry confirm low detection limit including aged fingerprints favorable orbital separation dpi – det dpi – dcn simultaneous chemical sensing bridges chemical sensing selective hydrazine detection resolution latent fingerprint rationally designed imidazole detailed forensic analysis based hydrazine sensing forensic applications hydrazine 1 </ sup phase sensing security applications resolution imaging imidazole fluorophores forensic imaging based fluorophore ” response work establishes strongly electron photophysical characteristics nucleophilic addition level iii integrates reaction integrated materials integrated analytical highly toxic h nmr ester analogue effective solid demand rapid clearly resolved beyond solution 94 μm Hydrazine is a highly toxic, potentially carcinogenic compound widely used in industry, necessitating sensitive detection. Meanwhile, latent fingerprint identification requires high-contrast, high-resolution imaging. Both demand rapid and visually discernible signals, motivating the development of integrated materials for simultaneous chemical sensing and forensic imaging. Herein, we report a rationally designed imidazole-based fluorophore, DPI–DCN, that integrates reaction-based hydrazine sensing with high-resolution latent fingerprint (LFP) visualization. By incorporating a strongly electron-withdrawing dicyanovinyl unit, DPI–DCN establishes an efficient donor–acceptor framework, leading to enhanced intramolecular charge transfer (ICT) and pronounced bathochromic shifts relative to its ester analogue, DPI–DET. These photophysical characteristics are supported by density functional theory calculations, which reveal a reduced HOMO–LUMO gap and favorable orbital separation. DPI–DCN exhibits excellent selectivity toward hydrazine, displaying a distinct fluorescence “turn-off” response with a low detection limit of 1.94 μM. Mechanistic investigations using ¹H NMR and mass spectrometry confirm that nucleophilic addition of hydrazine to the dicyanovinyl moiety disrupts π-conjugation and suppresses ICT, accounting for the observed optical changes. Beyond solution-phase sensing, DPI–DCN functions as an effective solid-state fluorescent powder for LFP development, enabling high-contrast imaging across diverse substrates, including aged fingerprints. Notably, multilevel fingerprint features up to level III are clearly resolved, demonstrating its capability for detailed forensic analysis. This work establishes a direct structure–property–function relationship and presents a versatile molecular platform that bridges chemical sensing and forensic imaging, offering new opportunities for integrated analytical and security applications. 2026-10-01T00:00:00Z Text Journal contribution 10.1021/acsomega.6c06606.s001 https://figshare.com/articles/journal_contribution/Structure_Driven_Intramolecular_Charge_Transfer_Modulation_in_Imidazole_Fluorophores_for_Selective_Hydrazine_Detection_and_Forensic_Applications/34041459 CC BY-NC 4.0