Gold Nanoclusters and Silica-Coated Carbon Dots-Assisted Ratiometric Fluorescent Nanosensors for Ultrasensitive Detection of Glyphosate

Abstract

In this work, a novel ratiometric fluorescent nanosensor by coupling mesoporous silica spheres-coated nitrogen-doped carbon dots (N-CDs@SiO 2 ) and bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs) was developed for sensitive detection of glyphosate. BSA-AuNCs nanocomposites were covalently connected onto the surface of amino-functionalized N-CDs@SiO 2 nanospheres, causing the core-satellite probes with two fluorescence emissions at 436 and 651 nm, respectively, under a single excitation of 360 nm. The N-CDs@SiO 2 @BSA-AuNCs "signal on−off−on" ratiometric fluorescent probes could realize highly selective differentiation and accurate detection of glyphosate based on the fluorescence quenching of Cu 2+ on BSA-AuNCs and glyphosate-induced fluorescence recovery due to the strong complexation of glyphosate toward Cu 2+ . The developed ratiometric fluorescent nanosensor exhibited excellent selectivity to glyphosate, wide detectability in a concentration range of 5−100 ng/mL, high sensitivity with a low detection limit of 3.4 ng/mL, as well as fascinating reliability and practicability in real malt samples with recoveries of 94.81−101.61%. This study provides a universal platform for versatile sensing of more trace analytes in complex matrices and can be extended for wide application in the environment and food safety fields.

Carbon Nanomaterial Fluorescent Probes and Their Biological Applications

“…This section presents a review of the research surrounding the application of CNMs in environmental optical sensing, focusing on post-2019 literature (Table ). Key focal areas encompass sensing of pathogens, ,− explosives and contaminants, − metal ions, − volatile organic compounds (VOCs), − plant hormones, − and ROS/RNS. − For a more detailed overview of the broad use of CNMs as fluorescence sensors, readers may refer to the other reviews. − …”

“…(A) Ratiometric fluorescence responses of N-CDs@SiO 2 @BSA-AuNCs with Cu 2+ in response to glyphosate and seven other pesticides at a concentration of 100 ng/mL, and (B) the linear correlation between the I 436 / I 651 intensity ratio and glyphosate concentrations ranging from 5 to 100 ng/mL. Adapted from ref . Copyright 2023 American Chemical Society.…”

“…In the case of detecting contaminants, Ma et al developed a ratiometric fluorescent nanosensor aimed at detecting glyphosate, 1254 a widely used herbicide known for its nonselective, broad-spectrum weed control properties. This sensor integrates nitrogen-doped CDs enveloped in mesoporous silica spheres (N-CDs@SiO 2 ) with bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs).…”

Bismuth, Nitrogen-Codoped Carbon Dots as a Dual-Read Optical Sensing Platform for Highly Sensitive, Ultrarapid, Ratiometric Detection of Doxorubicin

“…Li et al developed iron, cobalt, and nitrogen-codoped CDs as a dual-signal biosensor to detect uric acid by a fluorescence and colorimetry method. The ratiometric fluorescence probe has emerged as a powerful tool for the precise and quantitative detection of various targets owing to its unique self-calibration function, which allows it to compensate for environmental and instrumental factors that could potentially interfere with the accuracy of the measurements. − In addition, the ratiometric fluorescence detection system has the advantage of multiple fluorescence color changes, making it easy to visualize. However, there are few reports on ratiometric and colorimetric dual-mode sensing DOX based on CDs.…”

Localized Surface Plasmon Resonance-Based Nanosensor for Rapid Detection of Glyphosate in Food Samples

“…At present, most methods employed to detect the presence of glyphosate in foodstuffs, such as liquid chromatography coupled to tandem mass spectrometry and capillary electrophoresis, although quite efficient, can be costly and require skilled personnel [16]. As efficiency goes, platforms based on nanosensors are rather versatile alternatives to the usual glyphosate detection methods, with detection limits as low as 3.4 ng•mL −1 having been reported for a fluorescent sensor that coupled gold nanoclusters to silica-coated carbon dots [17]. Furthermore, sensors based on the localized surface plasmon resonance ( LSPR) phenomenon displayed by nanostructures such as metallic nanoparticles emerge as viable, low-cost alternatives to further approach this issue [18][19][20][21][22][23].…”