A5060323290- Gold and Silver Nanoparticles Synthesis and Applications
- Pickering emulsions and particle stabilization
- Biosensors and Analytical Detection
- Plasmonic and Surface Plasmon Research
- Nanocluster Synthesis and Applications
- Quantum Dots Synthesis And Properties
- Advanced biosensing and bioanalysis techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Copper-based nanomaterials and applications
- Nanomaterials and Printing Technologies
- Machine Learning in Materials Science
- Nonlinear Optical Materials Studies
- Surfactants and Colloidal Systems
- Force Microscopy Techniques and Applications
- Protein Interaction Studies and Fluorescence Analysis
- Nanoporous metals and alloys
- Material Dynamics and Properties
- Advanced Sensor and Energy Harvesting Materials
- Polymer Surface Interaction Studies
- Laser-Ablation Synthesis of Nanoparticles
- Supramolecular Self-Assembly in Materials
- Micro and Nano Robotics
- Innovative Microfluidic and Catalytic Techniques Innovation
- Electrohydrodynamics and Fluid Dynamics
- Solar-Powered Water Purification Methods
Nanyang Technological University
2015-2024
Institute of Materials Research and Engineering
2017
National University of Singapore
2009-2013
Chinese University of Hong Kong
2011
Electrochemical nitrogen-to-ammonia fixation is emerging as a sustainable strategy to tackle the hydrogen- and energy-intensive operations by Haber-Bosch process for ammonia production. However, current electrochemical nitrogen reduction reaction (NRR) progress impeded overwhelming competition from hydrogen evolution (HER) across all traditional NRR catalysts requirement elevated temperature/pressure. We achieve both excellent selectivity (~90%) significant boost Faradic efficiency 10...
NaYF4:Yb,Er@SiO2@Ag core–shell nanocomposites were prepared to investigate metal-enhanced upconversion luminescence. Two sizes (15 and 30 nm) of Ag nanoparticles used. The emission intensity the nanocrystals was found be strongly modulated by presence (NPs) on outer shell layer nanocomposites. extent modulation depended separation distance between NPs nanocrystals. optimum luminescence enhancement observed at a 10 nm for with two different nm). A maximum 14.4-fold when 15 used 10.8-fold...
Public attention to the food scandals raises an urgent need develop effective and reliable methods detect contaminants. The current prevailing detections are primarily based upon liquid chromatography, mass spectroscopy, or colorimetric methods, which usually require sophisticated time-consuming steps sample preparation. Herein, we a facile strategy assemble vertically aligned monolayer of Au nanorods with nominal 0.8 nm gap distance demonstrate their applications in rapid detection...
Ag octahedron nanoparticles are assembled with graphene oxide (GO) sheets to form octahedron@GO hybrids. Owing the excellent chemical enhancement of GO, single particle SERS demonstrates an factor 9 × 10<sup>5</sup>, which is twice as large that a pure octahedron.
Most of the surface‐enhanced Raman scattering (SERS) substrates are 2D planar systems, which limits SERS active area to a single Cartesian plane. Here, we fabricate 3D with aim break traditional limitation, and extend hotspots into third dimension along z‐axis. Our tailored increased in z‐direction from tens nanometers micrometers, increasing by at least an order magnitude larger than confocal volume (∼1 μm) most spectrometers. Various hierarchical SERS‐active microstructures fabricated...
Population-wide surveillance of COVID-19 requires tests to be quick and accurate minimize community transmissions. The detection breath volatile organic compounds presents a promising option for but is currently limited by bulky instrumentation inflexible analysis protocol. Here, we design hand-held surface-enhanced Raman scattering-based breathalyzer identify infected individuals in under 5 min, achieving >95% sensitivity specificity across 501 participants regardless their displayed...
Integrating machine learning with surface-enhanced Raman scattering (SERS) accelerates the development of practical sensing devices. Such integration, in combination direct detection or indirect analyte capturing strategies, is key to achieving high predictive accuracies even complex matrices. However, in-depth understanding spectral variations arising from specific chemical interactions essential prevent model overfit. Herein, we design a machine-learning-driven "SERS taster" simultaneously...
Abstract A major challenge in nanoparticle self-assembly is programming the large-area organization of a single type anisotropic into distinct superlattices with tunable packing efficiencies. Here we utilize nanoscale surface chemistry to direct silver octahedra three two-dimensional plasmonic at liquid/liquid interface. Systematically tuning wettability leads continuous superlattice structural evolution, from close-packed progressively open structures. Notably, standing on vertices arranged...
Single-phase Cu2ZnSnS4 (CZTS) is an essential prerequisite toward a high-efficiency thin-film solar cell device. Herein, the selective phase formation of single-phase CZTS nanoparticles by ligand control reported. Surface-enhanced Raman scattering (SERS) spectroscopy demonstrated for first time as characterization tool to differentiate mixed compositional (e.g., CZTS, CTS, and ZnS), which cannot be distinguished X-ray diffraction. Due superior selectivity sensitivity SERS, growth mechanism...
The refractive index change-based plasmonic sensing with noble metal nanocrystals has been demonstrated unambiguously in a number of studies. sensitivity and figure merit are two key parameters for this type sensing. Here, we report our studies the effects multipolar plasmon resonances on nanocrystals. Ag nanocubes 84 nm edge length found to exhibit well-defined dipolar, quadrupolar, octupolar resonances. dipolar resonance highest 336 nm/RIU (refractive unit), while quadrupolar possesses...
An analytical platform suitable for trace detection using a small volume of analyte is pertinent to the field toxin and criminology. Plasmonic nanostructures provide surface-enhanced Raman scattering (SERS) that can potentially achieve toxins and/or molecules detection. However, highly diluted, samples remains challenge. Here, we fabricate superhydrophobic SERS by assembling Ag nanocubes support strong surface plasmon chemical functionalization with sample just 1 μL. Our strategy integrates...
Surface-enhanced Raman scattering (SERS) is a molecular-specific spectroscopic technique that provides up to 1010-fold enhancement of signature fingerprints using nanometer-scale 0D 2D platforms. Over the past decades, 3D SERS platforms with additional plasmonic materials in z-axis have been fabricated at sub-micrometer centimeter scale, achieving higher hotspot density all x, y, and z spatial directions tolerance laser misalignment. Moreover, flexibility construct arbitrary sizes shapes...
Successful translation of laboratory-based surface-enhanced Raman scattering (SERS) platforms to clinical applications requires multiplex and ultratrace detection small biomarker molecules from a complex biofluid. However, these generally exhibit low cross sections do not possess specific affinity plasmonic nanoparticle surfaces, significantly increasing the challenge detecting them at concentrations. Herein, we demonstrate "confine-and-capture" approach for two families urine metabolites...
Abstract Inspired by aphids, liquid marbles have been studied extensively and found application as isolated microreactors, micropumps, in sensing. However, current liquid‐marble‐based sensing methodologies are limited to qualitative colorimetry‐based detection. Herein we describe the fabrication of a plasmonic marble substrate‐less analytical platform which, when coupled with ultrasensitive SERS, enables simultaneous multiplex quantification identification ultratrace analytes across separate...
We demonstrate a multiplex plasmonic anti-counterfeiting platform by embedding multiple molecules on single substrate with superior nanometer scale spectral and spatial resolution. The encoded specific molecular information can be read out only using Raman spectroscopy. Multiplexing increases the complexity of these security labels without compromising
Chemical speciation and quantification at trace levels of toxic mercury methylmercury ions in water is achieved by SERS spectroscopy.
Two types of gold nanoparticles, nanocubes and nano-octahedra were prepared their nonlinear absorption properties investigated by using femtosecond open aperture Z-scan experiments. Both exhibited a shift from saturable (SA) to reverse (RSA) at higher excitation intensities. The SA behavior was ascribed ground state plasmon band bleaching RSA excited two-photon these materials. competition different processes is responsible for the observed switching behavior.
The effective number of surface-enhanced Raman spectroscopy (SERS) active hot spots on plasmonic nanostructures is the most crucial factor in ensuring high sensitivity SERS sensing platform. Here we demonstrate a chemical etching method to increase surface roughness one-dimensional Ag nanowires, targeted at creating more along nanowire's longitudinal axis for increased detection sensitivity. Silver nanowires were first synthesized by conventional polyol and then subjected NH(4)OH H(2)O(2)...
Localized photoluminescence manipulation of 1L-MoS2 is achieved by using single shape-controlled Ag nanoantenna. By varying the antenna morphology, continuously tunable from enhanced (>2-fold) to weakened states. A heterogeneous optical platform realized depositing various antennas on same , with an unprecedented range output being observed simultaneously.
Interfacial self-assembly of nanoparticles is capable creating large-area close-packed structures for a variety applications. However, monolayers hydrophilic cetyltrimethylammonium bromide (CTAB)-coated Au are challenging to assemble via interfacial self-assembly. This report presents facile and scalable process fabricate monolayer films ultrathin CTAB-coated nanoprisms at the air-water interface using Langmuir-Schaefer technique. first achieved by one-step functionalization with...
Current plasmonic metasurfaces of nanocubes are limited to planar configurations, restricting the ability create tailored local electromagnetic fields. Here, we report a new chemical strategy achieve tunable with nonplanar nanocube orientations, creating novel lattice-dependent field localization patterns. We manipulate interfacial behaviors Ag by controlling ratio hydrophilic/hydrophobic molecules added in binary thiol mixture during surface functionalization step. The orientation at an...
Organizing nanoparticles into supercrystals comprising multiple structures remains challenging. Here, we achieve one assembly with dual for Ag polyhedral building blocks, truncated cubes, cuboctahedra, octahedra, and octahedra. We create two micro-environments in a solvent evaporation-driven system: at the drying front air/water interface. Dynamic flow concentrates polyhedra front, generating hard particle behaviors leading to morphology-dependent densest-packed bulk supercrystals. In...
Two-photon lithography (TPL) is an emerging approach to fabricate complex multifunctional micro/nanostructures. This because TPL can easily develop various 2D and 3D structures on a variety of surfaces, there has been rapidly expanding pool processable photoresists create different materials. However, challenges in developing two-photon currently impede progress TPL. In this review, we critically discuss the importance photoresist formulation We begin by evaluating commercial design...