Silicon Quantum Dot-Based Fluorescent Probe: Synthesis Characterization and Recognition of Thiocyanate in Human Blood

Abstract

Allylamine-functionalized silicon quantum dots (ASQDs) of high photostability are synthesized by a robust inverse micelle method to use the material as a fluorescent probe for selective recognition of thiocyanate (a biomarker of a smoker and a nonsmoker). The synthesized ASQDs were characterized by absorption, emission, and Fourier transform infrared spectroscopy. Surface morphology is studied by transmission electron microscopy and dynamic light scattering. The synthesized material exhibits desirable fluorescence behavior with a high quantum yield. A selective and accurate (up to 10–10 M) method of sensing of thiocyanate anion is developed based on fluorescence amplification and quenching of ASQDs. The sensing mechanism is investigated and interpreted with a crystal clear mechanistic approach through the modified Stern–Volmer plot. The developed material and the method is applied to recognize the anion in the human blood sample for identification of the degree of smoking. The material deserves high potentiality in the field of bio-medical science.

Silicon Nanocrystals and Their Composites: Syntheses, Fluorescence Mechanisms, and Biological Applications

“…In recent years, varieties of methods of functionalizing the Si NCs surface with s complex surface have been carried out to adjust the fluorescence properties of Si NCs by introducing various surface ligands such as amino, alkenyl, alkynyl, and aryl groups. Roy et al developed a method for allylamine-functionalized silicon quantum dots. The mixture prepared by the method exhibited strong fluorescence, and the PLQY of the composite in an aqueous environment was found to be 37%.…”

How to identify a smoker: a salient crystallographic approach to detect thiocyanate content

“…Therefore, 1 can act as a biomarker in the blood of smokers and non-smokers by differential quenching of fluorescence intensity. 45 …”

Designed Synthesis of Dual Emitting Silicon Quantum Dot for Cell Imaging: Direct Labeling of Alpha 2-HS-Glycoprotein

“…The spectrum of SQDs exhibited the characteristic peaks at 3225 (broad band of ν N−H stretch ), 2126 (ν C−H stretch ), 1600 (sharp band due to the ν N−H bending ), 54 1485 (scissoring of Si-CH 2 ), 1326 (symmetric bending of Si-CH 2 ), 1091 (ν Si−O−Si stretch ), and 686 cm −1 (ν Si−O−Si bending ). 24,55 Therefore, spectral position and nature indicated the presence of primary amine groups (along with Si−C and Si−O linkages) in the synthesized SQDs (Scheme S-1).…”

“…16−18 As a result, QDs possess a wide range of applications in various fields such as bioimaging, 7,19 photonics, 20 optoelectronics, 21 biosensing, 22 and chemical sensing. 23,24 However, the use of metal based QDs is limited due to the environmental and physiological safety issues. For example, Cd-based quantum dots emit toxic Cd 2+ ions in the biological environment.…”