• A highly functionalized fluorescent chemoprobe based on isoquinoline was reported. • It displayed excellent recognition ability towards m-CPBA in 99 % aq. ACN solution. • The limit of detection was determined to be as low as 0.93 µM. • Comparative FT-IR, NMR , mass spectral, and DFT studies were performed. • Test-strips and an RGB-Arduino device were developed enabling real-time detection. The development of fluorescent organic small-molecular probes targeting m-Chloroperoxybenzoic acid (m-CPBA) detection is crucial to effectively mitigate associated health and ecological hazards. Isoquinoline scaffold, despite its inherent attributes, has not undergone thorough exploration as a fluorescence platform, primarily owing to synthetic complexities. In the current work, we described the design, synthesis, and utilization of a novel thiomethyl-appended isoquinoline-based chemoprobe (QN) for the chemosignaling of extensively used peroxy acid m-CPBA. QN exhibits high fluorescence quantum yield (Φ f = 0.54) and demonstrates excellent sensing ability towards m-CPBA in nearly aqueous solution via the intramolecular charge transfer (ICT)-off mechanism. It was proposed that m-CPBA promoted oxidative transformations of QN into corresponding sulfoxide and sulfone analogues contributes to its discriminative character towards m-CPBA. Comprehensive Fourier transform infrared (FT-IR), high resolution mass spectrum (HRMS) analyses, and density functional theory (DFT) studies were conducted to substantiate the proposed mechanistic pathways. The limit of detection of m-CPBA with QN was determined to be 0.93 µM. Furthermore, the practicality of QN was enhanced through integration into sensing test strips allowing solid-phase detection of m-CPBA. In addition, a low-cost optosensing device based on an open-source Arduino platform, interfaced with a red, green, and blue (RGB) color sensor has been developed which enables instant quantifiable analysis of varying m-CPBA concentrations in real-time conditions.

New Julolidine substituted phthalocyanine dyes developed in this work exhibit being cost-effective and simple to produce. FTIR, MALDI-TOF, UV-visible, and NMR analysis verified the structural properties of the dyes. The dyes did not clump and were soluble in a wide range of organic solvents. The dyes ZnPc, NiPc, CoPc and CuPc are completely transparent in solution. The dye’s thermal stability and transmittance were measured using thermogravimetric analysis (TGA) and UV-visible spectroscopy. Among the other produced dyes, ZnPc (17%) spin-coated films had the lowest light scattering process and the maximum transmittance (83%) in the blue area. Finally, the combined results revealed that ZnPc dye might be employed as an LCD color filter.

• A highly functionalized fluorescent chemoprobe based on isoquinoline was reported. • It displayed excellent recognition ability towards m-CPBA in 99 % aq. ACN solution. • The limit of detection was determined to be as low as 0.93 µM. • Comparative FT-IR, NMR , mass spectral, and DFT studies were performed. • Test-strips and an RGB-Arduino device were developed enabling real-time detection. The development of fluorescent organic small-molecular probes targeting m-Chloroperoxybenzoic acid (m-CPBA) detection is crucial to effectively mitigate associated health and ecological hazards. Isoquinoline scaffold, despite its inherent attributes, has not undergone thorough exploration as a fluorescence platform, primarily owing to synthetic complexities. In the current work, we described the design, synthesis, and utilization of a novel thiomethyl-appended isoquinoline-based chemoprobe (QN) for the chemosignaling of extensively used peroxy acid m-CPBA. QN exhibits high fluorescence quantum yield (Φ f = 0.54) and demonstrates excellent sensing ability towards m-CPBA in nearly aqueous solution via the intramolecular charge transfer (ICT)-off mechanism. It was proposed that m-CPBA promoted oxidative transformations of QN into corresponding sulfoxide and sulfone analogues contributes to its discriminative character towards m-CPBA. Comprehensive Fourier transform infrared (FT-IR), high resolution mass spectrum (HRMS) analyses, and density functional theory (DFT) studies were conducted to substantiate the proposed mechanistic pathways. The limit of detection of m-CPBA with QN was determined to be 0.93 µM. Furthermore, the practicality of QN was enhanced through integration into sensing test strips allowing solid-phase detection of m-CPBA. In addition, a low-cost optosensing device based on an open-source Arduino platform, interfaced with a red, green, and blue (RGB) color sensor has been developed which enables instant quantifiable analysis of varying m-CPBA concentrations in real-time conditions.