Ratiometric Fluorescence Platform Based on Modified Silicon Quantum Dots and Its Logic Gate Performance

Abstract

A novel optical nanoprobe based on silicon quantum dots (SiQDs) has been assembled through a one-pot low-temperature (40 °C) treatment by using 3-(aminopropyl)trimethoxysilane (APTMS) and ascorbic acid (AA) as two precursors. The water-soluble SiQDs demonstrate intense green luminescence in aqueous environment and the excitation-dependent feature has been explored. Meanwhile, the incorporation of salicylaldehyde (SA) serves to suppress the emission of SiQDs effectively via nucleophilic reaction and an "on-off" change is observed. Furthermore, the addition of Zn can lead to evolution of emission peaks, and the green band at 500 nm gradually shifts toward the blue side at 455 nm. The corresponding ratiometric signal changes ( I/ I) can accurately determine the Zn concentration and the limit of detection is calculated to be 0.17 μM in the linear range between 1 and 100 μM. In this research, a molecular logic gate (AND) system has been well established by using SA and Zn as two inputs. The fluorescence emission changes based on SiQDs will shed new light on the development of functional sensors at the nanoscale level.

Application of Zero-Dimensional Nanomaterials in Biosensing

“…In addition, the addition of Zn 2+ led to the evolution of emission peak. The green band at 500 nm gradually shifted to the blue direction at 455 nm, and corresponding changes in the ratiometric signal (I 455 / I 500 ) could accurately reflect the concentration of Zn 2+ , with a detection limit of 0.17 µM (Li et al, 2018d). These fluorescence emission changes based on SiQDs would provide a new idea for the development of nanoscale functional sensors.…”

Synthesis and application of coumarin fluorescence probes

“…In contrast to the general instrumental methods, uorescence analyses have many outstanding features under physiological conditions, such as high sensitivity 1,2 or selectivity, 2,3 simple manipulations, 4,5 low cost, 5 rapid response rate, 6 real-time detection, 7 spatiotemporal resolution 8 and facile visualization. 9,10 In the past decade, a wide variety of uorescent probes with different recognition moieties have been designed, which were based on the most versatile uorophores, including uorescein, 11 coumarin, cyanine, 12 boron-dipyrromethene (BOD-IPY), 13 rhodamine, and 1,8-naphthalimide.…”

Dual-Channel Probe of Carbon Dots Cooperating with Lanthanide Complex Employed for Simultaneously Distinguishing and Sequentially Detecting Tetracycline and Oxytetracycline

“…The molecularly imprinted polymers (MIPs) prepared by this molecular imprinting technique have specific recognition and selective adsorption properties, which are simple and low-cost choices for improving fluorescence detection selectivity [ 31 , 32 , 33 ]. On the other hand, the construction of dual-channel ratio fluorescence probe, may effectively avoid the problems of low sensitivity and susceptibility to external environment interference from the on-off fluorescence switch sensor, and realize rapid visual detection through the change of fluorescence colors [ 34 , 35 ].…”