Luminescence Nanoprobe in the Near-Infrared-II Window for Ultrasensitive Detection of Hypochlorite

Abstract

Sensitive and selective detection of hypochlorite is in great demand for food safety, especially in fresh cold chain products. However, the detection limit of traditional visible emission-based strategies cannot satisfy the requirement of ultrasensitive analysis in practical applications. In this work, we explored a novel luminescent nanoprobe in the near-infrared-II (NIR-II) window to greatly improve the hypochlorite detection limit for analysis of real milk samples, which was based on the fluorescence resonance energy-transfer process between the hypochlorite-responsive dye (FD1080) and the lanthanide-doped downconverted nanoparticles. Specifically, the NIR-II luminescence from Yb ions was first suppressed by FD1080 due to the energy-transfer mechanism. In the presence of hypochlorite, FD1080 was bleached to recover the luminescence. As a proof-of-concept, the optimal nanoprobe exhibited a linear luminescence recovery in the range of 0.1–1 nM with the detection limit of 0.0295 nM for hypochlorite. Real milk sample detection experiments showed that the probe had good accuracy and precision.

Management of fluorescent organic/inorganic nanohybrids for biomedical applications in the NIR-II region

“…10E). 96 After reacting with ClO À , the NIR-II fluorescence intensity of nanohybrids recovered due to the destruction of FD-1080 (Fig. 10F and G).…”

Aggregation-Induced Emission Fluorophore-Incorporated Curcumin-Based Ratiometric Nanoprobe for Hypochlorite Detection in Food Matrices

“…When compared with other reported assays, this as-proposed AIE Curcumin/TPE@ HyNPs demonstrated a comparable or even better sensitivity for reporting the residual ClO − (Table S3). In particular, it needs to be mentioned that this sensitivity toward ClO − was inferior to the allowable threshold of 0.97 μM (0.05 ppm) by the Chinese national food safety standard, 9 illustrating a feasibility for employing this as-proposed AIE Curcumin/ TPE@HyNPs to precisely report the residual levels of ClO − in real food matrices and thus safeguarding food safety. Past experience has taught us that the selectivity is considered as the priority to assess the practical potential of this as-proposed AIE fluorophore-doped ratiometric fluorescent nanoprobe Curcumin/TPE@HyNPs, because the real food matrix is usually very complex.…”

“…For instance, the Chinese national food safety standard sets the residual threshold of ClO − in food matrices at 0.97 μM (0.05 ppm), whereas the European Union absolutely forbids its use in meat-related products. 9 In view of this, it is very imperative and desirable to develop an efficient, precise, economical, and reliable analytical technique for yielding the efficient early detection of ClO − residues in food matrices, particularly during its massive use against the COVID-19 epidemic.…”

“…As a highly efficient disinfectant and bleach, hypochlorite (ClO – ) is sometimes used to perform food preservation (e.g., raw milk and meat-related products) and water treatment. − Nevertheless, the excess ClO – is also capable of breaking the nutritional composition of food, primarily attributable to its strong oxidation capacity, thereby affecting the flavor and quality of food. , In addition, the excessive intake of ClO – through food chains may lead to neurodegeneration, methemoglobinemia, lung injury, etc., harming public health. − Under this circumstance, authorities around the world have specified the maximum allowable residual threshold of ClO – in various food matrices. For instance, the Chinese national food safety standard sets the residual threshold of ClO – in food matrices at 0.97 μM (0.05 ppm), whereas the European Union absolutely forbids its use in meat-related products . In view of this, it is very imperative and desirable to develop an efficient, precise, economical, and reliable analytical technique for yielding the efficient early detection of ClO – residues in food matrices, particularly during its massive use against the COVID-19 epidemic.…”

Tumor microenvironment enhanced NIR II fluorescence imaging for tumor precise surgery navigation via tetrasulfide mesoporous silica-coated Nd-based rare-earth nanocrystals

“…Due to sensitivity and specificity limitation, long time acquisition as well as ionizing radiation risk that above imaging modalities are not applicable to intraoperative navigation. Fortunately, in vivo NIR fluorescence imaging has developed as a non-invasive tool for enhancing staging tumor diagnosis, especially, it has unique advantages in guiding tumor resection due to its high-spatial-resolution and instantaneity [ [10] , [11] , [12] , [13] ]. The US Food and Drug Administration (FDA) has approved clinical useable contrast agents in the first near-infrared window (NIR I, 750–900 ​nm), like indocyanine green (ICG) [ 14 ] and methylene blue (MB) [ 15 ] which have been extensively explored for variety tumor margin delineation; however, short time of tumor retention, photo bleaching and rapid systematic clearance have impended these fluorophores for fluorescence imaging guided tumor surgery in vivo [ 16 ].…”