Zitong Wu

A novel biosensor based on single-layer MoS2 nanosheets for detection of Ag+

In this work, we use for the first time single layer MoS2 as the fluorescence quencher to design a detection method for Ag(+) with excellent robustness, selectivity and sensitivity. To maintain the ultrathin MoS2, bulk MoS2 materials have been exfoliated by intercalation with lithium followed by reaction with water. As-prepared two-dimensional MoS2 not only has good water-solubility but also obtains high fluorescence quenching efficiency within 5 min. Importantly, the detection limit of this assay for Ag(+) (1 nM) was lower than the maximum limitation guided by the United States Environmental Protection Agency (EPA) and the World Health Organization (WHO). Further, this new Ag(+) probe was demonstrated in monitoring Ag(+) in lake water samples with satisfactory results.

Simple, rapid, homogeneous oligonucleotides colorimetric detection based on non-aggregated gold nanoparticles

A simple, rapid colorimetry for DNA detection based on non-aggregated gold nanoparticles and magnetic beads has been developed with high selectivity and sensitivity.

Colorimetric response of peptide modified gold nanoparticles: An original assay for ultrasensitive silver detection.

In this article, we for the first time present an original and ultrasensitive assay to detect Ag+ ions, with which the aggregation of the given peptide-modified gold nanoparticles (peptide-AuNPs) can be triggered by the interaction between peptides and Ag+. The approach has rarely been used in the colorimetric determination of Ag+, because the mechanism of the above-mentioned interaction has not been studied through. In our assay, the principle of this interaction was investigated. Moreover, we applied it in the design of an extremely sensitive sensor for Ag+ detection with great selectivity. It is the Ag+-induced folding structure of the peptides that leads to the aggregation of peptide-AuNPs. The aggregation involves the formation of 4-coordinated complexes between Ag+ and peptides via bonding with the carbonyl oxygen and the nitrogen of the α-amino group in the peptides. The result shows that Ag+ ions can be selectively detected as low as 7.4nM with a linear range of 10-1000nM. Compared with other approaches, the proposed approach demonstrates superior simplicity, sensitivity, stability and time-saving. Furthermore, the biosensor excels in the practical application in water samples (e.g., lake, tap and drinking water) owing to its non-interference and on-site rapid determination.

A novel platform for detection of protooncogene based on Au nanocluster enhanced fluorescence

For the first time, gold nanoclusters were found to exhibit high fluorescence enhancement ability based on the metal-enhanced fluorescence (MEF) effect, which can effectively enhance the fluorescence of fluorescein isothiocyanate (FITC). By means of this phenomenon, Au nanoclusters have been successfully used in the construction of a fluorescence-enhanced sensing platform for the detection of protooncogene.

Bi-detection system for separation-free simultaneous determination of erythrosine and sucrose in candy floss

A bi-detection system integrated by laser-induced fluorescence (LIF) and retro-reflected beam interference (RBI) based refractive index was established and applied to simultaneously determine erythrosine and sucrose in candy floss. The system realized separation-free analysis of candy floss without prior concentration steps.

INHIBIT‐Inspired Two‐Output DNA Logic Gates Based on Surface‐Enhanced Raman Scattering

Herein, we presented a novel logic gate based on an INHIBITION gate that performs parallel readouts. Logic gates performing INHIBITION and YES/OR were constructed using surface-enhanced Raman scattering as optical outputs for the first time. The strategy allowed for simultaneous reading of outputs in one tube. The applicability of this strategy has been successfully exemplified in the construction of half-adder using the two-output logic gates as reporting gates. This reporting strategy provides additional design flexibility for dynamic DNA devices.

A one-tube multiplexed colorimetric strategy based on plasmonic nanoparticles combined with non-negative matrix factorization

Herein, a one-tube colorimetric platform has been developed for the simultaneous determination of two analytes (DNA as model object) in one tube with picomolar sensitivity. SPR-active nanoparticles are used to encode reporter probes sensitive to oligonucleotides associated with hepatitis A virus Vall7 polyprotein gene (HVA) and hepatitis B virus surface-antigen gene (HVB) respectively and magnetic beads (MBs) serve as the removal tool. In this mixed nanoparticles based biosensor, the addition of target analytes could change the concentration of each nanoparticle, leading to different colors of the supernatant. The influence of spectral overlap has been eliminated by a non-negative matrix factorization (NMF). With the assistance of NMF, the limit of detection (LOD) can be determinated as pM level without amplification. On the whole, this nanosensor boasts the advantages of high sensitivity and low sample consumption. Simultaneous colorimetric detection and quantification of two molecules in one tube are demonstrated.