Advances in single quantum dot-based nanosensors

Abstract

Single-molecule detection provides a simple and ultrasensitive platform to quantify target molecules by simply counting the individual fluorescence signals. Quantum dots (QDs) are novel semiconductor nanocrystals with distinct characteristics of high brightness, large Stokes shift and broad absorption spectra, high molar extinction coefficients, high quantum yield, good photostability and long fluorescence lifetime. The combination of single-molecule detection with QDs enables the development of single QD-based nanosensors with extremely high sensitivity. Single QD-based nanosensors may be divided into two categories based on single QD burst coincidence detection and single QD-fluorescence resonance energy transfer (FRET) detection, and have significant advantages of high signal-to-noise ratio, high sensitivity, rapidity, and low sample consumption. The single QD-based nanosensors have the capability of directly detecting low-abundance species without the need for nucleic acid amplification, and may elucidate a variety of biological and biochemical phenomena in real time using single QD tracking. In this review, we summarize the recent advances in single QD-based nanosensors and their applications for sensitive detection of DNAs, microRNAs, proteins, enzymes, small molecules and viruses. We highlight the challenges and future direction of single QD-based nanosensors as well.

A single quantum dot-based nanosensor with multilayer of multiple acceptors for ultrasensitive detection of human alkyladenine DNA glycosylase

“…QDs have found wide applications in imaging, sensing, drug delivery and biomedical research 27–32. Recently, the combination of QDs with single-molecule/particle detection33–37 enables the detection of nucleic acids, proteins, and even small molecules with extremely high sensitivity, low sample consumption, rapidity, and simplicity 38–40. In this research, we develop a single QD-based nanosensor with multilayer of multiple acceptors for ultrasensitive detection of hAAG using apurinic/apyrimidinic endonuclease 1 (APE1)-assisted cyclic cleavage-mediated signal amplification in combination with the DNA polymerase-assisted multiple Cy5-mediated FRET.…”

Optical Sensors Based on II-VI Quantum Dots

“…Due to the extremely important functions of proteins, it is necessary to monitor their concentration and the processes in which they take part [19,71,72,73,74,75]. QDs-based FRET nanosensors have been developed to monitor a variety of enzymes including alkaline phosphatase, ATPase renin, protein kinase, DNA methyltransferase, DNA glycosylase, and telomerase [76]. A different strategies for determination of proteins are presented in Table 3.…”

High‐Performance Biosensing Systems Based on Various Nanomaterials as Signal Transducers

“…FRET-based FIs have also been investigated for biosensing platforms. [86][87][88][89][90] The FRET effect is a unique and interesting optical phenomenon that occurs between different types of fluorescent materials that possess different bandgap energies for fluorescence irradiation. [91][92][93] In this case, energy transfer takes place from the higher bandgap energy to the lower bandgap energy through dipole-dipole interactions within the range of approximately 10 nm.…”

“…FRET‐based FIs have also been investigated for biosensing platforms . The FRET effect is a unique and interesting optical phenomenon that occurs between different types of fluorescent materials that possess different bandgap energies for fluorescence irradiation .…”