An array of nanoscale-recessed ring-disk electrodes was fabricated using layer-by-layer deposition, nanosphere lithography, and a multistep reactive ion etching process. The resulting device operated in generator-collector mode by holding the ring at constant potential performing cyclic voltammetry sweeping disk Fe(CN)6(3-/4-) solutions. Steady-state response enhanced (~10×) limiting current were achieved cycling redox couple between with high transfer/collection efficiency. collector (ring)...

Nanoporous metal films are promising substrates for surfaced-enhanced Raman scattering (SERS) measurement, owing to their homogeneity, large surface area, and abundant hot-spots. Herein, a facile procedure was developed fabricate nanoporous Ag film on various substrate surfaces. Thermally deposited first treated with O2 plasma, resulting in porous Ag/AgxO (AgxO-NF) nanoscale feature. Sodium citrate then used reduce AgxO Ag, forming (AgNF) similar morphology. The AgNF demonstrates 30-fold...

In canonical electrochemical experiments, a high-concentration background electrolyte is used, carrying the vast majority of current between macroscopic electrodes, thus minimizing contribution electromigration transport redox-active species being studied. contrast, here large enhancements are achieved in absence supporting during cyclic voltammetry at recessed ring-disk nanoelectrode array (RRDE) by taking advantage redox cycling effect combination with ion enrichment and an unshielded...

Ion permselectivity can lead to accumulation in zero-dimensional nanopores, producing a significant increase ion concentration, an effect which may be combined with unscreened migration improve sensitivity electrochemical measurements, as demonstrated by the enormous current amplification (∼2000-fold) previously observed nanopore electrode arrays (NEA) absence of supporting electrolyte. Ionic strength is key experimental factor that governs magnitude additional (AFad) beyond simple redox...

Arrays of recessed ring–disk (RRD) electrodes with nanoscale spacing fabricated by multilayer deposition, nanosphere lithography, and multistep reactive ion etching were incorporated into nanofluidic channels. These arrays, which characteristically exhibit redox cycling leading to current amplification during cyclic voltammetry, can selectively analyze electroactive species based on differences in reversibility, potential, or both. Using Ru(NH3)63+ ascorbic acid (AA) as model reversible...

The acid-base chemistry of 2-mercaptobenzoic acid (2-MBA) immobilized on a polycrystalline silver surface was investigated by surface-enhanced Raman spectroscopy under potential control. COO(-) bending mode the benzoate form and C-COOH stretching benzoic 2-MBA were used to determine relative deprotonated protonated populations bound ligand, respectively. In addition, shifts in symmetric carboxylate reveal interactions between group surface, which could be displaced acetate other buffer...

Self-induced redox cycling at nanopore ring-disk electrodes is coupled, through a bipolar electrode, to remote fluorigenic reporter reaction.

Abstract Electrochemical reactions occurring at the opposite ends of bipolar electrodes (BPEs) are necessarily coupled, enabling electron transfer events one end to be read out optically, for example, by coupling fluorogenic other end. To explore potential this technique studying multiple redox events, arrays parallel BPE interdigitated electrode (IDEAs) were fabricated and integrated with separate analytical reporter microfluidic channels, respectively, in a closed configuration. The...

Electrochemical reactions at nanoscale structures possess unique characteristics, <italic>e.g.</italic> fast mass transport, high signal-to-noise ratio low concentration, and insignificant ohmic losses even electrolyte concentrations. These properties motivate the fabrication of density, laterally ordered arrays nanopores, embedding vertically stacked metal–insulator–metal electrode exhibiting precisely controlled pore size interpore spacing for use in redox cycling. recessed ring-disk...

Bipolar electrodes (BPE) are electrically floating metallic elements placed in electrified fluids that enable the coupling of anodic and cathodic redox reactions at opposite ends by electron transfer through electrode. One particularly compelling application allows one end a closed BPE to be read out optically inducing redox-initiated change optical response function reporter system other end. Here, BPE-enabled method for electrochemical sensing based on electrochromic methyl viologen (MV)...

Adsorption of 11-mercaptoundecanoic acid (MUA) on silver from methanol and aqueous solutions was monitored in situ by surface-enhanced Raman scattering (SRES) spectroscopy. While adsorption MUA is a one-step formation thiol-bound monolayer, SERS spectra reveal that monolayer solution involves interactions both carboxylate thiol groups with the surface. Several bands, including ν(C–S), νs(COO–), ν(C–C), were used to investigate evolution structure adsorbed surfaces. The time-dependent...

Surface charge characteristics and the electrical double layer (EDL) effect govern transport of ions into out nanopores, producing a permselective concentration polarization, which dominates electrochemical response nanoelectrodes in solutions low ionic strength. In this study, highly ordered, zero-dimensional nanopore electrode arrays (NEAs), with each presenting pair recessed electrodes, were fabricated to couple EDL effects redox cycling, thereby achieving detection improved sensitivity...

Control of permeability phospholipid vesicle (liposome) membranes is critical to their applications in analytical sensing, fundamental studies chemistry small volumes, and encapsulation release payloads for site-directed drug delivery. Applications liposome formulations delivery often take advantage the enhanced at gel-to-fluid phase transition, where encapsulated molecules can be initiated by an increase temperature. Despite numerous successful methods study kinetics, this process has been...

In this work, we in situ monitor the laser annealing of template-fabricated silver substrates using surface-enhanced Raman scattering (SERS) and 4-mercaptobenzoic acid (4-MBA) as a molecular probe. The process, which exhibits strong dependence on power, yields large (>50×) increase SERS immobilized 4-MBA. This increased response is correlated with changing substrate morphology optical scanning electron microscope images. We attribute enhancement to formation nanogaps facilitated by binding...

Traditional trajectory clustering algorithms mostly cluster trajectories from the perspective of temporal or spatial. However, with and spatial similarity may be semantically related, ignoring semantic information lead to unreasonable results. Besides, most existing cannot deal overlapping well. In this paper, we propose a based on improved label propagation core structure, which could better measure spaces network. Experimental results demonstrate that proposed algorithm can effectively...

Modern warfare has become increasingly expensive as a result of its multi-domain joint systematic combat model. To achieve the purpose stopping war with and maintaining safety people's lives property, paralyzing target system systems (SoS) operational capability maximally under constraints, such battlefield resources environment, an urgent research topic. This paper addresses problem fast search for optimal solution strike selection task, which considers dynamic coupling node states,...

Abstract A wavelet algorithm based on the generation of adaptive filter coefficients for resolution and quantitative analysis overlapping multicomponent chromatogram was proposed. In algorithm, filters are constructed by an optimization approach using correlation coefficient between peak areas component concentrations as criterion. By application method to simulated data with different noise level degree, it proved that satisfactory recoveries can be obtained when degree (R s ) is larger...

Chemical modification of the surfaces surface-enhanced Raman spectroscopy (SERS)-active metals with thin molecular layers expands variety species that can be attracted to SERS surface from solution. This approach provide selective detection new classes molecules would not otherwise detectable through direct interaction a SERS-active metal. For example, polycyclic aromatic compounds aqueous solution gold or silver substrates are modified alkylsilanes alkanethiols. While n-alkane monolayers...

The theory of evidence reasoning has been applied to collective decision-making in recent years. However, existing distributed fusion methods lead participants' preference leakage and failures as they directly exchange raw do not assess credibility like centralized credible (CCEF) does. To so, a privacy-preserving method with three-level consensus (PCEF) is proposed this paper. In difference measure (EDM) neighbor consensus, an evidence-free equivalent expression EDM among neighbored agents...