Multicomponent Array Research Articles

Comprehensive Qualitative and Quantitative Colorimetric Sensing of Volatile Organic Compounds Using Monolayered Metal-Organic Framework Films.

Cross-responsive chemical sensors are in high demand owing to their ability to distinguish a broad range of analytes. In this study, a vapochromic sensor array based on metal-organic frameworks (MOFs), which exhibits distinct patterns when exposed to volatile organic compounds (VOCs) and humidity, is developed. Conventional sensor arrays consist of various receptors that produce different responses. The vapochromic MOF-based sensor comprises dicopper paddlewheel clusters and dimethylamine azobenzene as binary colorimetric sensing moieties. Upon exposure to VOCs, the constructed sensor encompasses a broad spectrum of colors, ranging from green to red. Furthermore, the color of the MOF is influenced by the solvent used during the pretreatment. Consequently, monolayered MOF thin films can be adapted to multicomponent array systems by immersing the MOF in different solvents. This system provides both qualitative and quantitative sensing, generating unique color patterns corresponding to specific VOC types. Notably, the sensor successfully discriminates each of 14 common VOCs and water and accurately categorizes unknown samples. Moreover, the system undergoes reversible color changes in response to humidity, obviating the need for high-temperature regeneration steps. This novel approach offers insights into the versatile applications of MOFs by creating a colorimetric sensor array capable of detecting various analytes.

A Novel Quantitative Multi-Component Serological Assay for SARS-CoV-2 Vaccine Evaluation.

A multi-component microarray, applying a novel analysis algorithm, was developed for quantitative evaluation of the SARS-CoV-2 vaccines’ immunogenicity. The array enables simultaneous quantitation of IgG, IgM, and IgA, specific to the SARS-CoV-2 spike, receptor binding domain, and nucleocapsid proteins. The developed methodology is based on calculating an apparent immunoglobulin signal from the linear range of the fluorescent read-outs generated by scanning the microarray slides at different exposure times. A dedicated algorithm, employing a rigorous set of embedded conditions, then generates a normalized signal for each of the unique assays. Qualification of the multi-component array performance (evaluating linearity, extended dynamic-range, specificity, precision, and accuracy) was carried out with an in-house COVID-19, qRT-PCR positive serum, as well as pre-pandemic commercial negative sera. Results were compared to the WHO international standard for anti-SARS-CoV-2 immunoglobulins. Specific IgG, IgM, and IgA signals obtained by this array enabled successful discrimination between SARS-CoV-2 q-RT-PCR positive (seroconverted SARS-CoV-2 patients) and negative (naïve) samples. This array is currently used for evaluation of the humoral response to BriLife, the VSV-based Israeli vaccine during phase I/II clinical trials.

Multicomponent High-throughput Drug Screening via Inkjet Printing to Verify the Effect of Immunosuppressive Drugs on Immune T Lymphocytes

High-throughput drug screening based on a multi-component array can be used to identify a variety of interaction between cells and drugs for suitable purposes. The signaling of immune cells is affected by specific proteins, diverse drug combinations, and certain immunosuppressive drugs. The effect of a drug on an organism is usually complex and involves interactions at multiple levels. Herein, we developed a multilayer fabricating system through the high-throughput assembly of nanofilms with inkjet printing to investigate the effects of immunosuppressive drugs. Immunosuppressive drugs or agents occasionally cause side effects depending on drug combinations or a patient’s condition. By incorporating various drug combinations for understanding interaction between drugs and immune cells, we were able to develop an immunological drug screening kit with immunosuppressive drugs. Moreover, the ability to control the combination of drugs, as well as their potential for high-throughput preparation should be of great benefit to the biomedical and bioanalytical field.

Growing ordered arrays of vertically aligned copolymer nanowires for supercapacitors with high stability

In this report, we present a novel platform to study the formation of delicate ordered vertically aligned copolymer nanowires array with EDOT and Py as the initial source. The resultant samples exhibit a specific capacitance of 187 F g−1 with the current of 0.1 A g−1 in 0.1 M LiClO4 aqueous electrolyte. When the current was set as 8 A g−1, the energy density was 16.9 W h kg−1 and the power density was 5480 W kg−1 with good cycling stability (remained stable after 5000 cycles). The multicomponent copolymer nanowire array has great potential to become a versatile and efficient material for next generation of endurable electrochemical supercapacitors.

Versatile bisethynyl[60]fulleropyrrolidine scaffolds for mimicking artificial light-harvesting photoreaction centers.

Fullerene-based tetrads, triads, and dyads are presented in which [60]fulleropyrrolidine synthons are linked to an oligo(p-phenyleneethynylene) antenna at the nitrogen atom and to electron-donor phenothiazine (PTZ) and/or ferrocene (Fc) moieties at the α carbon of the pyrrolidine cycle through an acetylene spacer. Cyclic voltammetry and UV/ Vis absorption spectra evidence negligible ground-state electronic interactions among the subunits. By contrast, strong excited-state interactions are detected upon selective light irradiation of the antenna (UV) or of the fullerene scaffold (Vis). When only PTZ is present as electron donor, photoinduced electron transfer to the fullerene unit is unambiguously detected in benzonitrile, but this is not the case when Fc is part of the multicomponent system. These results suggest that Fc is a formidable energy transfer quencher and caution should be used in choosing it as electron donor to promote efficient charge separation in multicomponent arrays.

Vacuum soft lithography to direct neuronal polarization

The ability to coat surfaces with pre-determined patterns of biomolecules by soft lithography has found use in areas ranging from fundamental biology to translational medicine, such as tissue engineering and diagnostics. However, existing surface patterning techniques (e.g., microcontact printing and traditional lithography) are unable to pattern several biomolecules in a single step. Here we introduce a simple method to simultaneously pattern multiple biomolecules in complex two-dimensional configurations onto substrates with better than 2 µm resolution. This protocol, termed vacuum soft lithography, utilized below ambient pressures temporarily stored within a removable microfluidic template to expose specific regions of a substrate to multiple biochemical solutions. We demonstrate the utility of this vacuum soft lithography technique by fabricating a multi-component array that directs the adhesion, polarization, and neurite guidance of primary hippocampal neurons.

Identification of Bacteria by Conjugated Oligoelectrolyte/Single-Stranded DNA Electrostatic Complexes

Electrostatic complexes containing a cationic conjugated oligoelectrolyte (COE) and fluorescein (FAM)-labeled single-stranded DNA (ssDNA) serve as the basis for identifying various bacteria. The approach involves the preparation of five COE/ssDNA(x)-FAM electrostatic complexes, which differ in the ssDNA composition and which provide different photoluminescence (PL) spectra as a result of different degrees of energy transfer efficiency from the COE to FAM. Changes in the PL spectra upon addition of the bacteria can be quantified, and the differential response from the five ssDNAs gives rise to a multicomponent array response that allows identification of the microorganism under investigation.

Electronic Energy Transfer to the S2 Level of the Acceptor in Functionalised Boron Dipyrromethene Dyes

Taking the high road: Highly efficient electronic energy transfer takes place from a set of appended aryl polycyclic hydrocarbons to an expanded boron dipyrromethene (Bodipy)-based dye (see figure) despite negligible spectral overlap with the lowest-energy excited state localised on the acceptor.A multi-component array has been constructed around an expanded boron dipyrromethene (Bodipy) dye that absorbs and emits in the far-red region. One of the appendages is a perylene-based moiety that is connected to the boron atom of the terminal Bodipy by a 1,4-diethynylphenylene connector. Despite the fact that there is almost negligible spectral overlap between fluorescence from the perylene unit and absorption by the Bodipy residue, electronic energy transfer is rapid and essentially quantitative. It is concluded that at least half of the photons absorbed by perylene are transferred to the upper-lying singlet excited state (S(2)) associated with the Bodipy-based acceptor. The second appendage is a pyrene unit that is covalently linked to fluorene, through an ethynylene spacer, and to the boron atom of the Bodipy terminus, through a 1,4-diethynylphenylene connector. Pyrene absorbs and emits at higher energy than perylene and there is strong spectral overlap with the Bodipy-based S(2) state, and none with the corresponding S(1) state. Electronic energy transfer is now very fast and exclusively to the S(2) state of the acceptor. It is difficult to compute reasonable estimates for the rates of Coulombic energy transfer, because of uncertainties in the orientation factor, but the principle mechanism is believed to arise from electron exchange. Comparison with an earlier array built around a conventional Bodipy dye indicates that there are comparable electronic coupling matrix elements for the two systems. It is notable that pyrene is more strongly coupled to the Bodipy unit than perylene in both arrays. These new arrays function as highly effective solar concentrators.

Signal Extraction and Automated Polarization Analysis of Multicomponent Array Data

We present a method to extract seismic signals from three-component array data and estimate their polarization properties at each station. The technique is based on a singular value decomposition (SVD) of the complex three-component analytic signal and applies to linearly as well as elliptically polarized seismic phases. To increase accuracy we simultaneously analyze data from different stations and apply a noise weighting based on prearrival data. For polarization analysis, an au- tomated routine is also included. The automated routine selects the data window with the best signal-to-noise ratio from which to obtain a polarization. A linearity measure and a confidence interval accompany the polarization estimate at each station in the array. We test our technique for automated polarization analysis on synthetic P-wave data and compare results with those from other methods. A microseismic dataset from the North Sea provides a unique opportunity to statistically compare previous and independently obtained P-wave polarizations with those provided by the auto- mated technique presented here. We conclude that, for P-wave polarization analysis, our method is robust and significantly more accurate than conventional, mainly man- ual methods. This is especially so on data with polarized and correlating background noise. It is also faster and provides meaningful quality estimates.

Fullerohelicates: A New Class of Fullerene‐Containing Supermolecules.

A multicomponent array made of a bis-copper(I) helicate core and two peripheral fullerene subunits has been prepared and electron transfer from the photoexcited Cu(I)-complexed unit to C60 occurs.

Fullerohelicates: a new class of fullerene-containing supermolecules.

A multicomponent array made of a bis-copper(I) helicate core and two peripheral fullerene subunits has been prepared and electron transfer from the photoexcited Cu(I)-complexed unit to C60 occurs.

Ground and excited state electronic interactions in a bis(phenanthroline) copper(I) complex sandwiched between two fullerene subunits.

A new fullerene-substituted phenanthroline ligand has been obtained by reaction of a phenanthroline derivative bearing a 1,3-phenylenebis(methylene)-tethered bis-malonate with C(60) in a double Bingel cyclopropanation. The relative position of the two cyclopropane rings in the resulting bis-methanofullerene derivatives has been determined on the basis of the molecular symmetry (C(s)()) deduced from the (1)H and (13)C NMR spectra. The corresponding Cu(I) complex F-Cu-F has been prepared in good yields by treatment of the ligand with Cu(CH(3)CN)(4)BF(4). In the resulting multicomponent system, both C(60) moieties are in a tangential orientation relative to their bridging phenyl ring, and the central bis(phenanthroline)Cu(I) core is sandwiched between the two carbon spheres. The electrochemical properties of F-Cu-F suggest the existence of ground-state electronic interactions in this multicomponent array based on the mutual effects exerted by the fullerene units to the bis(2,9-diphenyl-1,10-phenanthroline)Cu(I) complex and vice versa. Close vicinity and electronic interactions between the inorganic core and the peripheral fullerene units are also suggested by increased electronic absorption around 430 nm. The distance between the two moieties is estimated to be 4.3 A by molecular modeling studies. The excited-state properties of F-Cu-F have also been investigated. Photoinduced electron transfer from the central chromophore to the external fullerene units occurs but, surprisingly, only following population of the excited states of the central inorganic unit and not of the external carbon spheres. This is mainly attributed to kinetic factors related to the different nature of the two types of excited states involved, namely charge transfer (excitation on the metal-complexed moiety) vs a localized state (excitation on the fullerene units).

Detection of CO and O2 Using Tin Oxide Nanowire Sensors

Highly uniform SnO2 nanowires, with bulk electronic properties directed by their surface chemistry, have been produced by isolating and oxidizing tin nanowires selected from a template‐synthesized array. The nanowires act as sensitive, fast, stable, and reproducible gas sensors that can be easily integrated into a multi‐component array (see Figure).

Electronic Absorption Spectrum and Reduction Behavior of a Multicomponent, Trinuclear Ru(II) Species Containing 2,3-Bis(2'-pyridyl)pyrazine Bridging Ligands and 2,2'-Biquinoline Peripheral Ligands

Electronic absorption spectrum and reduction pattern of a trinuclear Ru(II) species containing 2,3-bis(2'-pyridyl)pyrazine bridging ligands and 2,2'-biquinoline peripheral ligands have been studied and compared with other multinuclear metal complexes of the same family of systems. The structural formula of the compound investigated is [RuCl2{Ru(biq)2(μ-2,3-dpp)}2]4+ (1; biq = 2,2'-biquinoline, 2,3-dpp = 2,3-bis(2'-pyridyl)pyrazine). The electronic absorption spectrum of 1 (in acetonitrile) is dominated by intense spin-allowed ligand-centred bands in the UV region and by moderately intense spin-allowed metal-to-ligand charge-transfer bands in the visible. The studied compound undergoes several quasireversible reduction processes in the potential window investigated (up to -1.20 V vs SCE in DMF): two successive one-electron reductions at -0.52 and -0.61 V, followed by two processes involving two closely-spaced one-electron reductions each. Extensive comparison with reduction patterns of closely related species allows to assign each process to specific subunits of the multicomponent array. The effect of the peripheral biq ligands on the electronic interaction between inner subunits is evidenced.

Triplet−Triplet Energy Transfer between Porphyrins Linked via a Ruthenium(II) Bisterpyridine Complex

The photophysical properties of a multicomponent array consisting of a free-base aryl-porphyrin and a gold(III) aryl-porphyrin, assembled via a central bis(terpyridine) ruthenium(II) complex, PH2−Ru−PAu, have been studied in low-temperature glassy media by steady state and time-resolved methods. Comparison of the photophysical properties of this triad with those of the reference molecular models and of the related dyads (Ru−PH2, Ru−PAu) allows the photoinduced processes occurring in PH2−Ru−PAu to be elucidated. The photoinduced processes in glassy media in the dyads Ru−PH2 and Ru−PAu are basically similar to those occurring at room temperature where the absorbed energy is transferred with 100% efficiency to the pertinent porphyrin lowest triplet state. For Ru-3PAu the decay to the ground state is similar to the model 3PAu and displays double-exponential behavior, while in the case of Ru−3PH2 some perturbing effect of the ruthenium center in accelerating the inter-system crossing to the ground state by the...

Evaporation of Multicomponent Drop Arrays

The conventional fuels that are used in the field of transportation are primarily composed of two or more components. Each component evaporates, mixes with hot oxidant gases, ignites, and burns. Since evaporation is the precursor of the sequence of events leading to combustion, the evaporation studies on the multi-component drops are essential for determining the governing parameters of spray evaporation. While single-component drop studies have been carried out extensively in the past, very limited literature exists on the multicomponent array evaporation. The present paper deals with the evaporation of multicomponent fuel droplets in an array using the recently developed point source method (PSM). First, the quasi-steady (QS) evaporation of an isolated, multicomponent droplet is briefly analyzed. The resultant governing equations, along with Raoult’s law and the Cox-Antoine relation, constitute the set of equations needed to arrive at the solutions for: (1) the droplet surface temperature, (2) the evaporation rate of each species, and (3) the vapor mass fraction of each species at the droplet surface. The PSM, which treats the droplet as a point mass source and heat sink, is then adopted to obtain an analytic expression for the evaporation rate of a multicomponent droplet in an array of liquid droplets. Defining the correction factor (η) as a ratio of the evaporation of a drop in an array to the evaporation rate of a similar isolated multi-component drop, an expression for the correction factor is obtained. The results of the point source method (PSM) are then compared with those obtained elsewhere for a three-drop array that uses the method of images (MOI). Excellent agreement is obtained. The treatment is then extended to a binary drop array to study the effect of interdrop spacing on vaporization. When the drops are close to each other, the evaporation rate of the droplet in the array containing the larger percentage of volatiles is higher than the rate under isolated conditions (η>1). The results qualitatively confirm the experimental data reported elsewhere. Parametric results were obtained for the effect of changing the composition on the correction factor and finally critical drop compositions in the binary array are given for which η>1. Even though the results for the average correction factor of the whole array of 2 to 9 drops obtained using PSM are almost the same as the results from MOI, the correction factor of the center drop under severe interaction may deviate from those results obtained with MOI.

Estimation of polarization and slowness in mixed wavefields

A new algorithm is developed for estimating the moveout velocities and polarization states in mixed wavefields recorded on multicomponent array data in the presence of random noise. The algorithm is applicable to a spatial and temporal data window in which more than two events are present. Three fundamental attributes of the waves are determined: polarization angle, apparent slowness, and the change in amplitude between adjacent detectors. In implementing the method, it is assumed that data is recorded at equispaced geophones located in a spatial window in which the three parameters are constant. Robustness is achieved by averaging the transfer matrix over all combinations of the subarrays that have the same transfer matrix. Application of a least‐squares criterion reduces the mathematics to an eigenvalue problem. The eigenvalues are complex, and their magnitude determines the amplitude change factor. The phase is a linear function of frequency with slope that determines the vertical slowness. The eigenvectors are the polarizations. The input data consists of the cross‐power spectra between subarrays that contain the same number of elements and are shifted by zero or one geophone separation. Examples illustrate the application of the algorithm to synthetic data. Numerical test results show that the performance of the method is not sensitive either to the time overlap between events or to the degree of similarity between waveforms.

SEISMIC NOISE ESTIMATION USING HORIZONTAL COMPONENTS

The use of seismometer arrays containing both horizontal‐ and vertical‐component instruments for attenuation of surface‐wave noise has been studied theoretically. If a process can be defined to estimate the vertical noise component by operating on the outputs of one or more horizontal‐component seismometers, the estimate may be subtracted from the vertical‐component record to improve signal‐to‐noise ratio. The exact waveforms of vertically‐incident signals must be preserved in an operation of this kind. Formulas are developed to describe the response of a system employing three components measured at a single point. This system is found to be useful only in cases where the noise is strongly directional. A physical separation between the vertical‐ and horizontal‐component instruments is necessary to resolve the difficulties caused by uncertainties in the sense of the propagation velocity vector and particle orbit vector. Formulas, derived for systems consisting of circular rings of radially‐oriented horizontals and a central vertical show, that useful noise rejection can be obtained even in the most unfavorable case of uniform azimuthal noise distribution. The performance of arrays of this kind is not affected very much by uncorrelated noise or Love‐wave noise. Comparisons with similar arrays containing only vertical‐component seismometers indicate that, for some of the noise models studied, the multicomponent array should provide useful noise rejection over a greater bandwidth and at longer wavelengths than an all‐vertical array with the same dimensions.