[en] A supersensitive chiroptical-responsive system of enantioselectively recognizing L- and D-tryptophan (Trp) based on ( +)-diacetyl-L-tartaric anhydride-functionalized 1,3,5-triformylphloroglucinol (DTA-functionalized Tp) was constructed for the first time. With a high fluorescence quantum yield of 15.2% and fluorescence lifetime of 57.6 μs, DTA-functionalized Tp as both fluorescent and chiral recognition nanoprobe was used for the discrimination of L- and D-Trp with excitation/emission maxima at 330/490 nm within 3 min. The linear range of the fluorescence sensing was 0.002–0.15 μg mL⁻¹, and the detection limit achieved 1.4 ng mL⁻¹. Furthermore, a smartphone was employed as a detector and processor to couple with the chiroptical-responsive nanoprobe for establishing a novel and visual integration system for rapid and real-time detection of chiral amino acids with a detection limit of 13 ng mL⁻¹. The spiked recoveries of L-Trp in two commercially available functional beverages ranged from 86.00 to 118.33% in fluorescence and smartphone-based sensing system. Based on the excellent chiroptical-responsive effects, high stability, and biocompatibility, the chiroptical-responsive nanoprobe was successfully applied to visual optosensing and fluorescence imaging in response to L- and D-Trp in HeLa cells. This discrimination methodology with high sensitivity and enantioselectively shows great potential for in-site visually monitoring chiral amino acids in real food samples and tracking physiological processes. Graphical abstract:

[en] Quantum-dots-doped covalent organic frameworks in a molecularly imprinted network (QDs-doped COFs@MIP) were developed for detection of nereistoxin (NRT)-related insecticide in tap water. The preparation of QDs-doped COFs@MIP was easy to accomplish via one-pot synthesis at room temperature. QDs-doped COFs@MIP quenched by targeting thiosultap due to the photoinduced charge transfer. A Brunauer–Emmett–Teller surface area of 186.20 m² g⁻¹ and a maximum adsorption capacity of 771 mg g⁻¹ of the QDs-doped COFs@MIP exhibited good selectivity and adsorption capacity. Direct fluorescence determination was established over the range 5–100 μg L⁻¹ (R² = 0.9959) with a detection limit of 1.60 μg L⁻¹. Furthermore, 86.5–106.5% recoveries of spiked tap water were achieved. The determination system was feasible for tracing the NRT-related insecticide with high accuracy and good repeatability and reproducibility.

[en] A robust multi-dimensional sensing array based on VBimBF₄B/MAA-anchored quantum dot (QD)-grafted covalent organic frameworks (COFs) [(V-M)/QD-grafted COFs] was established via one-pot strategy. The multi-dimensional sensing array has the outstanding advantages of physicochemical and thermal stability, large specific surface area, and regular pore structures. The assistance of ionic liquid VBimBF₄B enhanced the transduction efficiency, and the synergistic effect of COFs enhanced detection efficiency. The improved multi-dimensional sensing array by COFs and ionic liquid VBimBF₄B served to identify seven insecticides by non-specific interactions via hydrogen bonding, and the differences in the kinetics of the binding to the insecticides resulted in variation of the three-output channel (fluorescence, phosphorescence, and light scattering) signals, thus generating a distinct optical fingerprint. The unique fingerprint patterns of seven kinds of common insecticides at 200 μg L⁻¹ were successfully discriminated using principal component analysis and clustered heat map analysis. The multi-dimensional sensing array showed a response to seven insecticides based on three spectral channels over the range of 0.001–0.4 μg mL⁻¹ with a limit of detection of 1.08–18.68 μg L⁻¹. The spiked recovery of tap water was 79.86–134.22%, with RSD ranging from 0.89–14.9%. This study broadens the applications of sensing arrays technology and provides a promising building block for insecticide determination. Graphical abstract: