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

Abstract

The development of efficient, economic, reliable, and accurate monitoring of hypochlorite (ClO − ) in food matrices is in great demand for food safety assessment, particularly during its massive use against the COVID-19 epidemic. Here, we prepared an aggregation-induced emission (AIE) fluorophore tetraphenylethylene (TPE)-incorporated curcumin-based hybrid ratiometric fluorescence nanoprobe (Curcumin/TPE@HyNPs) through amphiphilic phospholipid polymer-powered nanoprecipitation, which exhibited a fast, highly sensitive, and selective response to the residual ClO − in real food matrices. Because of the inner filter effect (IFE) from curcumin toward TPE inside the nanoprobe, the bright fluorescence of TPE aggregation at ∼437 nm was effectively quenched, along with an enhanced fluorescence of curcumin at ∼478 nm. Once there was a ClO − residue in food matrices, ClO − triggered the oxidation of o-methoxyphenol inside curcumin and led to the almost complete absorption collapse, thereby terminating curcumin fluorescence at ∼478 nm and the IFE process. Accordingly, the fluorescence of TPE at ∼437 nm was recovered. In this case, a ratiometric fluorescent response of Curcumin/TPE@HyNPs toward the residual ClO − in food matrices (e.g., milk) was proposed with a low detection limit of 0.353 μM and a rapid response time of 140.0 s. Notably, the phospholipid polymer as the protection layer effectively reduced/evaded the nonspecific binding of signal reporters inside the nanoprobe, facilitating it to directly monitor the residual ClO − in real food matrices. This work provided a novel approach to utilize the unconventional AIE luminophors for constructing the efficient and reliable early warning mechanisms toward various food contaminants.

Nanoassemblies Based on a Cationic Perylene Diimide Derivative and Sodium Dodecyl Sulfate: A Simple Fluorescent Platform for Efficient Analysis of Aflatoxin B1

“…The Stern–Volmer (SV) equation was further applied to quantitatively evaluate the quenching phenomenon of PdE-PDI/SDS toward AFB 1 (Figure B). The K sv value of PdE-PDI/SDS to AFB 1 was calculated to be 3.03 × 10 5 M –1 , which was much higher than that of PdE-PDI (7.45 × 10 4 M –1 ), suggesting that the import of SDS amplifies the quenching efficiency of PdE-PDI to AFB 1 . Subsequently, the spectra shown in Figure S9 exhibited that there was no overlap of the absorption spectrum of AFB 1 and the FL excitation/emission spectra of PdE-PDI/SDS, indicating the FL response of PdE-PDI/SDS did not result from fluorescence resonance energy transfer (FRET) and inner filter effect (IFE).…”

“…The K sv value of PdE-PDI/SDS to AFB 1 was calculated to be 3.03 × 10 5 M −1 , which was much higher than that of PdE-PDI (7.45 × 10 4 M −1 ), suggesting that the import of SDS amplifies the quenching efficiency of PdE-PDI to AFB 1 . 38 Subsequently, the spectra shown in Figure S9 exhibited that there was no overlap of the absorption spectrum of AFB 1 and the FL excitation/emission spectra of PdE-PDI/SDS, indicating the FL response of PdE-PDI/SDS did not result from fluorescence resonance energy transfer (FRET) and inner filter effect (IFE). According to the above results, the response of the system may be attributed to direct analyte-induced fluorescence quenching.…”

A Reaction-Based Ratiometric Bioluminescent Platform for Point-of-Care and Quantitative Detection Using a Smartphone

“…As a strong oxidant, HOCl is widely used in the disinfection of surfaces, fabrics, water, and food. In addition, excessive HOCl in food can destroy nutrients and cause adverse effects on human health . Therefore, it is of great importance to realize the real-time and accurate detection of HClO in complex environments.…”

Molybdenum disulfide nanostructures coupled with metal plasmonics for improved electronic and photonic performances

“…Nanotechnology-based colorimetric analysis has been largely established for diverse applications, such as environmental monitoring, food and drug safety. 65,66 The targets could play a role in the growth of hybrids, and the properties of the hybrids could respond to the concentrations of targets with high sensing performance. For instance, we previously reported that mercury could modulate the growth of Au plasmonic nanostructures on MoS 2 layers, and the LSPR performances of the resultant Au plasmonics were considered for the optical measurements of mercury ion concentrations.…”