Fluorescent and Colorimetric Dual-signal Enantiomers Recognition via Enzyme Catalysis: The Case of Glucose Enantiomers Using Nitrogen-doped Silicon Quantum Dots/Silver Probe Coupled with β-D-Glucose Oxidase

Abstract

Chiral enantiomers recognition is important but facing tough challenges in the direct quantitative determination for complex samples. In this work, via chosing nitrogen-doped silicon quantum dots (N-SiQD) as optical nanoprobe and constructing N-SiQD/silver (N-SiQD/Ag NPs) complex, β-D-GOx as model enzyme and glucose enantiomers as analytes, a fluorescent and colorimetric dualsignal chiral sensing strategy was proposed herein for chiral recognition based on specific enzymecatalyzed reaction. N-SiQD can exhibit intense fluorescence, while it can be quenched by Ag NPs owing to the formation of N-SiQD/Ag NPs. In the presence of glucose isomer, D-glucose is catalytically hydrolyzed by β-D-GOx to form H 2 O 2 owing to the specific enzyme catalyzed reaction between D-glucose and β-D-GOx, and H 2 O 2 can etch Ag NPs from the N-SiQD/Ag NPs probe to change the solution color from brown to colorless and restore the N-SiQD fluorescence; while these phenomena cannot be caused by L-glucose, a dual-signal sensing method was thus constructed for recognizing glucose enantiomers. It is believed that the chiral enantiomers recognition strategy via

Chiral Detection of Glucose: An Amino Acid-Assisted Surface-Enhanced Raman Scattering Strategy Showing Opposite Enantiomeric Effects on SERS Signals

“…In Table S1, we summarize some reported assays for the chiral discrimination of glucose enantiomers (Table S1). Based on the chirality selectors used, these methods can be divided into two categories, including (1) enzyme-based detection using glucose oxidase (GOx) and (2) non-enzyme-based detection. − The former category is the most used while the latter is much less used. The enzyme GOx is only responsive to d -Glu but not to l -Glu, thus realizing enantiomeric discrimination.…”

Integration detection of mercury(ii) and GSH with a fluorescent “on-off-on” switch sensor based on nitrogen, sulfur co-doped carbon dots

“…As an important zero-dimensional carbon-based nanometer material, carbon dots (CDs) have been studied since 2004 (ref. 1–4 ) and widely used in biological analysis, 5,6 sensing, 7–9 catalysis, 10,11 bioimaging 12 and photothermal therapy 13–15 and bio-medicine. 16 They have various properties, including stable fluorescence photoluminescence, 17,18 low toxicity, 19 excellent biocompatibility, 20 good water solubility 21,22 and low-cost synthesis.…”