Plasmon Enhanced IR Spectroelectrochemistry.

Plasmon-enhanced infrared (IR) techniques have garnered significant interest for their ability to achieve greatly more sensitive IR detection than conventional surface enhanced IR techniques. However, the difficulty in electrically connecting antennas has limited their application in IR spectroelectrochemistry, a crucial field for catalysis, analysis, and energy storage. Recent technical advancements have enabled the successful application of electrochemical potentials to antennas, making plasmon-enhanced IR spectroelectrochemistry feasible.

Key Structure Parameters for Designing High-Performance Substrates of Surface-Enhanced Infrared Absorption Spectroelectrochemistry.

Attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) plays a crucial role in understanding the interfacial reaction mechanisms at the molecular level, achieving an enhancement factor (EF) of up to 10. However, when this technique is integrated with electrochemistry (EC-ATR-SEIRAS), the EF is significantly reduced by ten- to hundred-fold. Thus, understanding of the key parameters that contribute to the EF is of great importance in designing high-performance substrates and extending the application for EC-SEIRAS.

Monitoring molecule translocation through plasmonic nanopores based on surface enhanced Raman scattering.

To study the translocation behavior of molecules through nanopores, the gold plasmonic nanopores (GPNs) structures with high Raman activity are fabricated. The process of molecule translocation (via potential, concentration and pH) is studied by Surface Enhanced Raman Scattering (SERS). The electrostatic effect is found critical for the translocation direction and speed of model molecule.

Emerging advances in biosensor technologies for quorum sensing signal molecules.

Quorum sensing is a physiological phenomenon of microbial cell-to-cell information exchange, which relies on the quorum sensing signal molecules (QSSMs) to communicate and coordinate collective processes. Quorum sensing enables bacteria to alter their behavior as the population density and species composition of the bacterial community change. Effective detection of QSSMs is paramount for regulating microbial community behavior.

Beta-Cyclodextrin-Modified Covalent Organic Framework Nanochannel for Electrochemical Chiral Recognition of Amino Acids.

The chiral recognition and separation of enantiomers are of great importance for biological research and the pharmaceutical industry. Preparing homochiral materials with adjustable size and chiral binding sites is beneficial for achieving an efficient chiral recognition performance. Here, a homochiral covalent organic framework membrane modified with β-cyclodextrin (CD-COF) was constructed, which was subsequently utilized as an electrochemical sensor for the enantioselective sensing of tryptophan (Trp) molecules.

Molecular Engineering of a Tumor-Targeting Thione-Derived Diketopyrrolopyrrole Photosensitizer to Attain NIR Excitation Over 850 nm for Efficient Dual Phototherapy.

Photosensitizers with near-infrared (NIR) excitation, especially above 800 nm which is highly desired for phototherapy, remain rare due to the fast nonradiative relaxation process induced by exciton-vibration coupling. Here, a diketopyrrolopyrrole-derived photosensitizer (DTPA-S) is developed via thionation of carbonyl groups within the diketopyrrolopyrrole skeleton, which results in a large bathochromic shift of 81 nm, endowing the photosensitizer with strong NIR absorption at 712 nm. DTPA-S is then introduced with a functional biomolecule (N-PEG-RGD) via click reaction for the construction of integrin αvβ3 receptor-targeted nano-micelles (NanoDTPA-S/RGD), which endows the photosensitizer with a further superlarge absorption redshift of 138 nm, thus extending the absorption maxima to ≈850 nm.

Sequence-Dependent Single-Molecule DNA Sensing Using Covalent Organic Framework Nanopores.

Enzyme-free single-molecule sequencing has the potential to significantly expand the application of nanopore technology to DNA, proteins, and saccharides. Despite their advantages over biological nanopores and natural suitability for enzyme-free single-molecule sequencing, conventional solid-state nanopores have not yet achieved single-molecule DNA sequencing. The biggest challenge for the accuracy of single-molecule sequencing using solid-state nanopores lies in the precise control of the pore size and conformity.

High-Throughput Single-Molecule Surface-Enhanced Raman Spectroscopic Profiling of Single-Amino Acid Substitutions in Peptides by a Gold Plasmonic Nanopore.

Simultaneous detection and structural characterization of protein variants on a single platform are highly desirable but technically challenging. Herein, we present a single-molecule spectral system based on a gold plasmonic nanopore for analyzing two peptides and their single-point mutated variants. The gold plasmonic nanopore enabled the high-throughput acquisition of surface-enhanced Raman scattering (SERS) spectra at the single-molecule level by electrically driving analytes into hot spots.

Nanometer-Resolved Mapping of Organic Cation Migration Behavior in Methylammonium Lead Halide Perovskites.

The performance and stability of organic metal halide perovskite (OMHP) optoelectronic devices have been associated with ion migration. Understanding of nanoscale resolved organic cation migration mechanism would facilitate structure engineering and commercialization of OMHP. Here, we report a three-dimensional approach for in situ nanoscale infrared imaging of organic ion migration behavior in OMHPs, enabling to distinguish migrations along grain boundary and in crystal lattice.

Surface-phonon-polariton-enhanced photoinduced dipole force for nanoscale infrared imaging.

The photoinduced dipole force (PiDF) is an attractive force arising from the Coulombic interaction between the light-induced dipoles on the illuminated tip and the sample. It shows extreme sample-tip distance and refractive index dependence, which is promising for nanoscale infrared (IR) imaging of ultrathin samples. However, the existence of PiDF in the mid-IR region has not been experimentally demonstrated due to the coexistence of photoinduced thermal force (PiTF), typically one to two orders of magnitude higher than PiDF.

Single-Molecule Discrimination of Saccharides Using Carbon Nitride Nanopores.

Structural complexity brings a huge challenge to the analysis of sugar chains. As a single-molecule sensor, nanopores have the potential to provide fingerprint information on saccharides. Traditionally, direct single-molecule saccharide detection with nanopores is hampered by their small size and weak affinity.

Synergistic Al-Al Dual-Atomic Site for Efficient Artificial Nitrogen Fixation.

Synthesis of ammonia by electrochemical nitrogen reduction reaction (NRR) is a promising alternative to the Haber-Bosch process. However, it is commonly obstructed by the high activation energy. Here, we report the design and synthesis of an Al-Al bonded dual atomic catalyst stabilized within an amorphous nitrogen-doped porous carbon matrix (AlNC) with high NRR performance.

Regulating ion affinity and dehydration of metal-organic framework sub-nanochannels for high-precision ion separation.

Membrane consisting of ordered sub-nanochannels has been pursued in ion separation technology to achieve applications including desalination, environment management, and energy conversion. However, high-precision ion separation has not yet been achieved owing to the lack of deep understanding of ion transport mechanism in confined environments. Biological ion channels can conduct ions with ultrahigh permeability and selectivity, which is inseparable from the important role of channel size and "ion-channel" interaction.

Molecular architectures of iron complexes for oxygen reduction catalysis-Activity enhancement by hydroxide ions coupling.

Developing cost-effective and high-performance electrocatalysts for oxygen reduction reaction (ORR) is critical for clean energy generation. Here, we propose an approach to the synthesis of iron phthalocyanine nanotubes (FePc NTs) as a highly active and selective electrocatalyst for ORR. The performance is significantly superior to FePc in randomly aggregated and molecularly dispersed states, as well as the commercial Pt/C catalyst.

Ultrasensitive Plasmon-Enhanced Infrared Spectroelectrochemistry.

IR spectroelectrochemistry (EC-IR) is a cutting-edge operando method for exploring electrochemical reaction mechanisms. However, detection of interfacial molecules is challenged by the limited sensitivity of existing EC-IR platforms due to the lack of high-enhancement substrates. Here, we propose an innovative plasmon-enhanced infrared spectroelectrochemistry (EC-PEIRS) platform to overcome this sensitivity limitation.

Atomic Force Microscopy-Based Nanoscale Infrared Techniques for Catalysis.

Atomic force microscopy (AFM)-based nanoscale infrared (nano-IR) techniques have found extensive application in the fields of chemistry, physics, and materials science, enabling the visualization of nanoscale features that surpass the optical diffraction limit. More recently, tentative investigations have been conducted into the use of these techniques in the field of catalysis, particularly in studying interfacial processes involving molecular monolayer samples. IR nanoimaging and nanospectroscopy offer unique perspectives on catalytic processes.

Unveiling the Solvent Effect in Plasmon Enhanced Electrochemistry the Nanoparticle-Impact Technique.

Plasmon-enhanced electrochemistry (PEEC) has been observed to facilitate energy conversion systems by converting light energy to chemical energy. However, comprehensively understanding the PEEC mechanism remains challenging due to the predominant use of ensemble-based methodologies on macroscopic electrodes, which fails to measure electron-transfer kinetics due to constraints from mass transport and the averaging effect. In this study, we have employed nanoparticle impact electrochemistry (NIE), a newly developed electroanalytical technique capable of measuring electrochemical dynamics at a single-nanoparticle level under optimal mass transport conditions, along with microscopic electron-transfer theory for data interpretation.

Core-Shell Reactor Partitioning Enzyme and Prodrug by ZIF-8 for NADPH-Sensitive In Situ Prodrug Activation.

Enzyme-prodrug therapies have shown unique advantages in efficiency, selectivity, and specificity of in vivo prodrug activation. However, precise spatiotemporal control of both the enzyme and its substrate at the target site, preservation of enzyme activity, and in situ substrate depletion due to low prodrug delivery efficiency continue to be great challenges. Here, we propose a novel core-shell reactor partitioning enzyme and prodrug by ZIF-8, which integrates an enzyme with its substrate and increases the drug loading capacity (DLC) using a prodrug as the building ligand to form a Zn-prodrug shell.

Photoenhanced Electrocatalytic Hydrogen Evolution Accelerated Dominantly by the Hot Electrons from Intraband Transition rather than Interband Transition.

Plasmonic materials enabling sunlight as an energy input to catalyze the hydrogen evolution reaction (HER) have become the research focus of artificial photosynthesis. Upon visible photoexcitation, there are both intraband transition and interband transition hot carriers generated, and which of them dominates the catalytic reaction remains elusive. Here, the contributions of hot electrons from intraband and interband transitions to the photoelectrocatalytic HER on plasmonic Au triangle nanoprisms (AuTNPs) have been studied.

Integrated separation and detection of exosomes a label-free magnetic SERS platform.

A label-free magnetic surface enhanced Raman scattering (SERS) platform was constructed, which was composed of superparamagnetic FeO nanoparticles as cores for separation and Au layers as shells for label-free SERS detection. Our method could effectively distinguish exosomes from different cell sources for cancer diagnosis and showed high sensitivity and specificity within a 95% confidence interval. As a low-cost and efficient exosome analysis method, the designed integrated platform for separation and detection has promising applicability in clinical diagnostics.

Ammonia-Induced Anomalous Ion Transport in Covalent Organic Framework Nanochannels.

More anomalous transport behaviors have been observed with the rapid progress in nanofabrication technology and characterization tools. The ions/molecules inside nanochannels can act dramatically different from those in the bulk systems and exhibit novel mechanisms. Here, we have reported the fabrication of a nanodevice, covalent organic frameworks covered theta pipette (CTP), that combine the advantages of theta pipette (TP), nanochannels framework, and field-effect transistors (FETs) for controlling and modulating the anomalous transport.