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A visual observation of the bending angle changes for the novel and easy detection of proteins is introduced in this study by fabricating bovine serum albumin (BSA) imprinted hydrogel strips with a one sided 3D porous structure using a combination of polystyrene colloidal crystal templating and the molecular imprinting approach using BSA as the template protein and several functional monomers.

Surface imprinting used for template recognition in nanocavities can be controlled and improved by surface morphological changes. Generally, the lithographic technique is used for surface patterning concerning sensing signal amplification in molecularly imprinted polymer (MIP) thin films. In this paper, we describe the effects of silanized silica molds on sensing the properties of MIP films. Porous imprinted poly(MAA–co–EGDMA) films were lithographically fabricated using silanized or non-treated normal silica replica molds to detect 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide as the standard template. The silanized mold MIP film (st-MIP) (Δf = −1021 Hz) exhibited a better sensing response than the non-treated normal MIP (n-MIP) (Δf = −978 Hz) because the imprinting effects, which occurred via functional groups on the silica surface, could be reduced through silane modification. Particularly, two non-imprinted (NIP) films (st-NIP and n-NIP) exhibited significantly different sensing responses. The st-NIP (Δfst-NIP = −332 Hz) films exhibited lower Δf values than the n-NIP film (Δfn-NIP = −610 Hz) owing to the remarkably reduced functionality against nonspecific adsorption. This phenomenon led to different imprinting factor (IF) values for the two MIP films (IFst-MIP = 3.38 and IFn-MIP = 1.86), which was calculated from the adsorbed 2,4-D mass per poly(MAA–co–EGDMA) unit weight (i.e., QMIP/QNIP). Moreover, it was found that the st-MIP film had better selectivity than the n-MIP film based on the sensing response of analogous herbicide solutions. As a result, it was revealed that the patterned molds’ chemical surface modification, which controls the surface functionality of imprinted films during photopolymerization, plays a role in fabricating enhanced sensing properties in patterned MIP films.

In this study, protein-imprinted sensors with thin bulk films were electrochemically fabricated on gold-coated quartz crystal electrodes with hemispherical porous gold patterns for detecting trypsin (Trp). The gold patterns were electrodeposited on a polystyrene colloidal monolayer and then rinsed using toluene. For Trp imprinting on the gold patterned electrodes, a thin layer with a poly(o-phenylenediamine) and Trp protein was formed using a cyclic voltammetry method under optimized conditions. In addition, a two-dimensional molecularly imprinted polymer (2D-MIP) film was prepared on a planar gold electrode under the same conditions to compare to the dependence of Trp selective recognition on three-dimensional (3D) thin MIP structure, and each corresponding nonimprinted polymer film were constructed by electropolymerization, in the absence of Trp template, to compare molecular imprinting effects. The sensing properties of Trp imprinted sensors were investigated using electrochemical, such as cyclic voltammetry and electrochemical impedance spectroscopy, and microgravimetric methods to confirm the sensitivity and selectivity of MIP films. The 3D-MIP films demonstrated a higher imprinting factor (3.51) in 48-μg/mL of Trp concentration than the 2D-MIP film, and the limit of detection was calculated to be 70.9-ng/mL. In addition, the films exhibited higher electrochemical sensing responses due to increased Trp recognition by the effective molecular imprinting over a larger surface area. Thus, the construction of 3D-MIP films for the protein imprinting could provide excellent specificity, faster kinetics, and higher sensitivity for detecting macromolecular proteins than 2D-MIP films.

This paper introduces a novel method to electrochemically grow surface imprinted poly(3-TAA-co-EDOT) patterns from a gold pinhole array inside an inverse silica opal monolayer for the detection of aspartame. Using colloidal lithography, the designed 2D silica opal photonic crystal acts as an insulating porous mask with exposed gold pinhole arrays to form molecularly imprinted conducting polymers (MICPs). As the number of cyclic voltammetry (CV) cycles is increased, the MICPs grew toward the silica inner wall retaining the imprinted pillar array formed on the gold pinholes. For all three types of MICP films investigated (i.e., CV1, CV3, and CV5), artificial recognition sites were successfully generated after aspartame extraction; aspartame adsorption was then investigated using quartz crystal microbalance measurements. In the case of MICP-CV5, all of its sensing properties such as sensing response (Δf), imprinting effect (If), and selectivity were found to be superior to those measured for the other polymers (i.e., MICP-CV1 and −CV3). Furthermore, the MICP-CV5 film demonstrated significantly enhanced sensing behavior relative to 2D inverse porous MICP (p-MICP) films with similar surface morphologies, which were grown electrochemically by conventional polystyrene colloidal lithography. Overall, the results presented herein clearly demonstrate that this novel lithographical method leads to an increased number of imprinting sites in MICP structures, which impart the resultant polymers with enhanced sensing properties.

Rotating cylindrical stamp-based nanoimprint technique has many advantages, including the continuous fabrication of intriguing micro/nanostructures and rapid pattern transfer on a large scale. Despite these advantages, the previous nanoimprint lithography has rarely been used for producing sophisticated nanoscale patterns on a non-planar substrate that has many extended applications. Here, the simple integration of nanoimprinting process with a help of a transparent stamp wrapped on the cylindrical roll and UV optical source in the core to enable high-throughput pattern transfer, particularly on a fabric substrate is demonstrated. Moreover, as a functional resin material, this innovative strategy involves a synergistic approach on the synthesis of molecularly imprinted polymer, which are spatially organized free-standing perforated nanostructures such as nano/microscale lines, posts, and holes patterns on various woven or nonwoven blank substrates. The proposed materials can serve as a self-encoded filtration medium for selective separation of formaldehyde molecules. It is envisioned that the combinatorial fabrication process and attractive material paves the way for designing next-generation separation systems in use to capture industrial or household toxic substances.

In this study, formaldehyde (HCHO)-imprinted hemispherical pore-patterned thin films, consisting of poly(2-(trifluoromethyl)acrylic acid–co–ethylene glycol dimethacrylate–co–styrene) (poly(TFMAA–co–EGDMA–co–ST)), were fabricated using the design of molecularly imprinted polymers (MIPs) and a subsequent lithographic micro/nanoimprinting method to amplify HCHO sensing signals in quartz crystal microbalance (QCM) sensors. Its molecular imprinting condition was optimized by controlling the added amount of a ST monomer in a MIP precursor solution. From the resonant frequency change with respect to HCHO adsorption, the imprinting factor of the porous MIP film was calculated to have a value of 2.38 and the sensitivity (0.132 mg g−1 ppm−1) of the porous MIP film exhibited markedly improved characteristics with respect to the porous non-imprinted polymer (NIP) film (0.05 mg g−1 ppm−1). The selectivity of the MIP-QCM sensors for the detection of HCHO was examined in the presence of other analogous toxic gases such as hydrogen chloride and hydrogen fluoride. The HCHO-absorbed porous MIP film had higher selective features with selectivity coefficients (k* ≈ 3.83 (HCl) and 4.46 (HF)) than porous NIP films (k* ≈ 1.53 (HCl) and 2.20 (HF)). Moreover, the relative selectivity of the porous MIP film appeared to be 2.03–2.5, which was higher than those of the planar MIP film (1.70–1.73).

New ionic conjugated polyelectrolyte complex films based on poly(3,4-ethylenedioxythiophene):sulfonated poly(diphenylacetylene) (PEDOT: SPDPA) are electrochemically formed on indium thin oxide substrates using a potentiostatic method, and their physical properties are evaluated using various analytical tools. Depending on a constant applied voltage, the surface morphological features and electrochemically doped states are different due to the conformational structure related to the oxidation state in the PEDOT growth process and concomitant SPDPA doping state in the films. For the purpose of use as a hole injection layer in organic light-emitting diodes, a well-known configuration (ITP/PEDOT:SPDPA/TPD/Alq3/LiF/Al) is adopted to investigate the optoelectronic properties.

Bisphenol A (BPA), which is extensively used in the plastic industry, is a known endocrine disrupting chemical whose release into the environment from industrial products is detrimental to human health. In this study, to characterize BPA-detectable imprinted films on quartz crystals (QCs), sensitive molecularly imprinted quartz crystal microbalance (MIP-QCM) sensors were fabricated. The MIP films were synthesized on 2D porous SiO2 and Au pinholes that were generally observed from replica structures prepared using a polystyrene colloidal monolayer as an insulating mold. For MIP film formation, surface-initiated atom transfer radical polymerization was precisely controlled to adjust the MIP film growth on initiator-modified porous structures. Note that three BPA-imprinted poly(4-VP-co-EGDMA) films, i.e., MIP(8-h), MIP(16-h), and MIP(24-h), under reaction time control were successfully prepared. Furthermore, all imprinted patterned surfaces were characterized via atomic force microscopy (AFM) and scanning electron microscopy (SEM). The MIP(24-h) film demonstrated the highest imprinting factor (i.e., IF ≈ 2.4) and sensitivity (i.e., 1.219 ± 0.079 Hz nM−1), although the maximum binding capacity (Qmax) and binding capacity (Qe) at 1-h rebinding equilibrium was relatively lesser than those of the MIP(8-h) and MIP(16-h) owing to the differentiation of the deposited MIP mass. Using the Freundlich isotherm model, the binding affinity of the BPA imprinted MIP films measured in an aqueous solution of BPA whose concentration ranged between 45 and 225 nM was evaluated. Finally, the selectivity of the MIP-QCM sensors for BPA detection was investigated in aqueous solutions in the presence of other analogous chemicals such as bisphenol F (BPF), bisphenol AP (BPAP), and bisphenol B (BPB). The MIP(8-h) film showed extremely high recovery percentage (≈ 94.54 %) owing to the relatively thinner film formation, which was significantly comparable with that of other MIP films, i.e., 68.37 % for MIP(16-h) and 61.99 % for MIP(24-h). However, the MIP(24-h) film appeared to have higher selective features with selectivity coefficients and relative selectivity (k* and k’ ≈ 2.5, respectively) despite measurement in a limited period (i.e., 1-h rebinding process).

Despite being one of the most widely used fungicides in the agricultural industry, iprodione is a known water pollutant, and its continuous release into water sources is detrimental to human health. In this study, sensitive molecularly imprinted quartz crystal microbalance (MIP–QCM) sensors were prepared by fabricating two types of frisbee-like pillar patterns (MIP-3 μm and MIP-5 μm) onto the surface of gold quartz crystals for the real-time detection of iprodione in aqueous solutions. This study describes the synthesis of iprodione-imprinted poly(methacrylic acid-co-2-(trifluoromethyl)acrylic acid-co-ethylene glycol dimethacrylate), referred to as poly(MAA–co–TFMAA–co–EGDMA), in combination with a micro-contact printing technique (μ-CP), via ultraviolet (UV)-assisted photopolymerization. The patterned surfaces with increased surface-to-volume (S/V) ratio were characterized via atomic force microscopy (AFM), scanning force microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The planar imprinted films and the corresponding non-imprinted films were prepared as the control samples for evaluating the sensor’s detection capabilities. According to the results, the MIP–QCM sensors had enhanced detection capabilities compared to their planar MIP counterparts owing to the increased binding affinity on the structured surfaces. The imprinting factor (IF) (i.e., Qe,MIP/Qe,NIP) indicated that the imprinting effects for each MIP film was comparatively assessed, resulting in the following order: 1.69 (MIP-plane)

In this paper, we examined a novel molecularly imprinted polymer (MIP) patterned matrix, consisting of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) as functional and cross-linking monomers, respectively, for detection of trace atrazine in an aqueous solution. A solvent assisted soft lithography and UV-initiated polymerization were used to develop striped poly(MAA-EGDMA) patterns. In comparison to a planar MIP film (Δ f p-MIP = −158 Hz), the striped patterns showed faster sensing response (Δ f s-MIP = −269 Hz) for the 30 min detection period due to the relatively increased binding sites generated from the MIP stripes. Furthermore, the sensitivity of the MIP sensor was found to be −9.98 Hz (μM) −1 via gravimetric quartz crystal microbalance (QCM) measurements and the selectivity of the MIP stripes was evaluated through sensing characteristics of other herbicides. Thus, a control of binding sites via this lithographic technique could contribute to the development of efficient MIP sensing platforms.

In this paper, we developed a novel molecularly imprinted conducting polymer (MICP) system consisting of porous poly(pyrrole-co-pyrrole-3-carboxylic acid) copolymer matrices for the recognition of theophylline (THEO), a drug molecule. Various porous MICP (p-MICP) films were made using colloidal lithography and examined via gravimetric technique [e.g. gold quartz crystal microbalances (QCMs)]. They showed faster sensing response than a planar MICP film due to the increased THEO binding sites obtained from porous structures. Thus, this lithographical approach to MICP sensors can enable the rebind of a specific template to be increased to achieve improved sensor capacity.

In this work, the formation of various polystyrene (PS) colloidal structures on striped PS patterns is demonstrated based on a simple and novel convective assembly method that controls the electrostatic interactions between the PS colloidal particles and sodium dodecyl sulfate (SDS). Under the optimal conditions (different withdrawal speeds, channel dimensions, suspension concentrations, etc.), highly ordered structures such as highly close-packed, zigzag, and linear colloidal aggregates are observed. In addition, these colloidal arrangements are used for development of molecularly imprinted polymer (MIP) sensors with highly improved sensing properties. Using PDMS replicas, three hemispherical poly(methacrylic acid-ethylene glycol dimethacrylate) (poly(MAA-EGDMA)) MIP films, including planar MIP and non-imprinted polymer (NIP) films, are photopolymerized for detection of trace atrazine in an aqueous solution. From gravimetric quartz crystal microbalance (QCM) measurements, a non-close-packed MIP film exhibits highest sensing response (Δf = 932 Hz) to atrazine detection among hemispherical MIP films and shows 6.5-fold higher sensing response than the planar MIP film. In addition, the sensitivity of the MIP sensor is equivalent to -119 Hz/(mol L(-1)). From the ratio of slopes of the calibration curves for the hemispherical MIP and NIP films, the imprinting factor (If) is as high as 11.0. The hemispherical MIP film also shows excellent selectivity in comparison with the sensing responses of other analogous herbicides. As a result, this molecular surface imprinting using PS colloidal arrays is highly efficient for herbicide detection.

This study analyzed the maltol quality, composition ratio of fatty acids, and contents of phenolic compounds in white ginseng extracts(four types), red ginseng extracts(five types), black ginseng extracts(two types), and Chinese ginseng extracts(nine types). By examining patterns in these measurements, we determined the characteristic factors of the extracts and measured the possibility of qualitative analysis. In the analysis of maltol using TLC, white ginseng extracts were not detected while red and black ginseng extracts were detected, so the possibility of detection was considered as a characteristic factor for qualitative analysis. Regarding the composition of fatty acids, palmitic and linoleic acids were the main fatty acids in the ginseng extracts palmitic acid was high in white ginseng extracts while linoleic was low in red ginseng extracts. Regarding the ratio(Pal/Lin) of the two fatty acids, there was a large difference between white ginseng extracts(56.7~64.3%) and red ginseng extracts(32.0~38.5%), and these figures seemed to be characteristic factors for the analysis. For the phenolic compounds, extracts contained maltol, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid. White ginseng extracts contained similar percentages of phenolic compounds while red ginseng extracts had high maltol content. According to the measurement results of the percentages of maltol and cinnamic acid, white ginseng extracts showed values below five, whereas red and black ginseng extracts showed 53~289, which was also a characteristic factor for qualitative analysis. Consequently, we found that we can differentiate between ginseng extracts using characteristic factors that we analyzed in an experiment on white ginseng extracts from China.

PURPOSE The purpose of this preliminary study was to investigate the effects of adding 4,4'-bis(N,N-diethylamino) benzophenone (DEABP) as a co-initiator to a binary photoinitiating system (camphorquinone-amine) to analyze on the degree of conversion (DC) of a light-cured resin for dental 3D printing. MATERIALS AND METHODS Cylindrical specimens (N=60, n=30 per group, ø5 mm × 1 mm) were fabricated using bisphenol A glycerolate dimethacrylate (BisGMA) both with and without DEABP. The freshly mixed resins were exposed to light in a custom-made closed chamber with nine light-emitting diode lamps (wavelength: 405 nm; power: 840 mW/cm2) for polymerization at each incidence of light-irradiation at 10, 30, 60, 180, and 300 seconds, while five specimens at a time were evaluated at each given irradiation point. Fourier-transform infrared (FTIR) spectroscopy was used to measure the DC values of the resins. Two-way analysis of variance and the Duncan post hoc test were used to analyze statistically significant differences between the groups and given times (α=.05). RESULTS In the DEABP-containing resin, the DC values were significantly higher at all points in time (P

Two consecutive green house experiments were carried out to examine the effect of Azospirillum spp. inoculation on growth, nitrogen and phosphorus accumulation in maize plants grown in pots. There were eight treatments including an uninoculated control and Azospirillum strains OAD-3, OAD-9, AZ-22, AZ-8, AZ-9, Azospirillum brasilense BR-11001 and Azospirillum lipoferum BR-11080. The inoculated plants showed higher values in each of the following measurements; plant height, total dry mass and nitrogen and phosphorus accumulation in shoot when compared to the uninoculated control plants in two consecutive experiments conducted in the same soil. Among Azospirillum strains, Azospirillum sp. OAD-3 inoculated plants showed higher nitrogen accumulation by 44.5% and 45.1%, total dry mass by 48.6% and 66.9% in two consecutive experiments respectively. The nitrogen concentration in the maize plants was not changed significantly in the first experiment, however it increased significantly in the second experiment due to Azospirillum inoculation. In addition, Azospirillum sp. OAD-9 and A. brasilense BR-11001 also proved to be effective with respect to total dry mass, total nitrogen accumulation and total phosphorus accumulation. The nitrogen concentrations in maize plants were increased in the second experiment due to Azospirillum inoculation.

Lettuce (Lactuca sativa L.) plants were grown under hydroponic system to characterize the diurnal change of nitrate concentration and nitrate uptake rate and to examine the effect of short term cold treatment to rhizosphere on nitrate concentration and uptake rate in lettuce plant. The nitrate concentrations in midrib were two times higher than those in leaf. Nitrate concentration in the shoot reached to minimum (8.7 mg-N/GDW) at 14:00 and, thereafter, increased continuously until 23:00. During 11:0017:00, nitrate uptake by lettuce plant was maximum (4.8 mg-N/GDW-Root/hr). Short term cold treatment reduced nitrate concentration in the shoot by 1418%, and nitrate uptake rate by 5055%, respectively. These results showed that short term cold treatment before harvest could be applied for the purpose of reduction of nitrate concentration in the leaf under hydroponic culture.