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A newly developed nonenzymatic electrochemical sensor for the determination of glucose using the HO-BiONO 3 nanocomposites is demonstrated. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transformation infrared (FTIR) spectra and cyclic voltammetry (CV) are used to characterize HO-BiONO 3 nanocomposites. Low cost, facile synthesis, low applied potential and enhanced catalytic response guarantee the extraordinary electrochemical performance of themodified nanomaterials. Based on its excellent electrocatalytic activity, a highly sensitive and stable amperometric glucose sensor was proposed. The sensor shows a linear range from 5.0 μM to 2.1 mM with a high sensitivity of 8.2 × 10 2 μA mM −1 cm −2 and a low detection limit of 0.12 μM. The common interferences, such as uric acid (UA), ascorbic acid (AA) and dopamine (DA), do not interfere with the detection of glucose. The proposed sensor is successfully applied to the determination of glucose in the real serum samples and shows good application potential in biological electrochemistry. [ABSTRACT FROM AUTHOR]

A new nonenzymatic glucose ECL sensor based on attapulgite (Att) integrated with semiconductor material TiO 2 was developed. The prepared material was characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Based on ECL experimental results, Att–TiO 2 composites were found to be able to improve the ECL properties of luminol. When glucose is added into the system, TiO 2 NPs serve as a catalyst and dissolved O 2 acts as a cosubstrate for the glucose oxidation reaction. Dissolved O 2 also worked as coreactant for the luminol ECL emission. Due to the consumption of dissolved O 2 , a quenching effect would appear on the luminol ECL emission. Under the optimized conditions, the linear logarithmic relationship between ECL intensity and the concentration of glucose was valid in the range from 1.0 mM to 1.0 nM ( R = 0.9976) with a detection limit (S/N = 3) of 10.0 pM. In addition, the proposed sensor presented good reproducibility, stability, and sensitivity for glucose detection and can be successfully applied in the determination of glucose in real blood samples. [ABSTRACT FROM AUTHOR]

A novel nonenzymatic electrochemiluminescence (ECL) sensor based on the perovskite LaTiO 3 -Ag0.1 nanomaterial is developed. The sensor displays high electrocatalytic activity with a linear range from 0.01 μM to 0.10 mM ( R = 0.9999), a detection limit of 2.50 × 10 −9 M (S/N = 3), and a sensitivity of 7.80 × 10 2 μA mM −1 cm −2 . Furthermore, it is successfully utilized for the detection of glucose in real blood samples. The results indicate that the perovskite LaTiO 3 -Ag0.1 nanocomposite is promising in electrochemical sensing and biosensing. [ABSTRACT FROM AUTHOR]

Schematic diagram of (A) preparation procedure of CG/Au@Ag nanocomposite and (B) the fabrication of proposed sensor using CG/Au@Ag nanocomposite. [Display omitted] • CG/Au@Ag nanocomposite was prepared via two-step reduction reaction. • The hybrid has excellent electrocatalytic properties for the oxidation of NO 2 − and I−. • A new electrochemical sensor was constructed for simultaneous detection of NO 2 − and I−. • The sensor was applied to the determination NO 2 − and I− in real water samples. Herein, a novel electrochemical sensor based on core-shell Au@Ag nanoparticles deposited on carboxylated graphene (CG) was constructed for the simultaneous electrochemical determination of nitrite (NO 2 −) and iodide (I−). The CG/Au@Ag nanocomposite was prepared via two-step simple chemical reduction method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the CG/Au@Ag nanocomposite. Au@Ag nanoparticles were distributed on the CG surface, providing more active sites for the electrocatalytic active center. The strong synergistic effect between Au@Ag nanoparticles and CG improved the conductivity of nanoparticles and provided a significant electrocatalytic performance on the flexible sensor. The CG/Au@Ag modified electrode showed a wide linear concentration range of 2.5–1250 μM, a low detection limit of 0.15 μM for NO 2 − and corresponding linear ranges of 3.5–1000 μM (peak I) and 500–1000 μM (peak II), and the detection limit of 0.1 μM for I−. It also demonstrated good anti-interference ability against various common interfering substances. Finally, the sensing platform was successfully applied to simultaneous determination of NO 2 − and I− in real samples. The present electrochemical strategy is promising to broaden the practical electrochemical application in environment. [ABSTRACT FROM AUTHOR]

• "Synergistic effect" has been applied into the design of paraquat (PQ) sensor. • The structure of tripodal-pillar[5]arenes TP5 could offer "Synergistic effect". • The TP5 could efficiently detect PQ and its LOD is 2.23 × 10−7 M. • The adsorption efficiency of the TP5 for PQ is up to 98.40 %. • Highly efficiency sensing and removal of PQ was achieved via the "Synergistic effect". Paraquat (PQ) plays a vital role in pesticide field, however, PQ always threatenhuman health owing to its high toxicity. Efficient detection and removal of PQ is an important and challenging task. Herein, a novel tripodal tri-pillar[5]arene-based sensor molecule (TP5) has been designed and synthesized. Interestingly, the designed tripodal tri-pillar[5]arene structure could offer a "synergistic effect" for the binding of PQ and achieve the fluorescence sensing. Through the "synergistic effect", two adjacent pillar[5]arene groups in each TP5 molecule could bind one PQ molecule by multi-non-covalent interactions. Based on the "synergistic effect", the sensor molecule TP5 has better sensing and removal efficiency toward PQ. The TP5 shows sensitivity fluorescence response for PQ and its lowest of detection limit (LOD) was 2.23 × 10−7 M. Meanwhile, TP5 -based test paper has been prepared, which could serve as a convenient and efficient test kit to detect PQ in water and the concentration range is 10-6 M ∼ 10-1 M in practical situations. Furthermore, the TP5 displayed the excellent ability for PQ adsorption in water. For example, the TP5 was applied to absorb commercial pesticide paraquat (PQ), the adsorption efficiency for PQ was up to 98.40 %. It is worth mentioning that, benefited from the "synergistic effect", the TP5 shows better adsorption property than activated charcoal and most single pillar[n]arene based adsorption materials. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe based on CdTe QDs coated with molecularly imprinted polymers (MIP) was prepared for the determination of leucomalachite green (LMG) with the method of synchronous fluorescence quenching. When the wavelength interval of excitation and emission positions (Δl) was set as 340 nm, the strongest synchronous fluorescence emission of MIP-coated QDs was achieved at 260 nm, enabling the maximum fluorescent quenching of LMG because of the inner filter effect. According to this principle, a synchronous fluorescence quenching method for the rapid detection of LMG in fish was developed. MIP-coated QDs were synthesized using acrylamide (AM) and ethylene glycol dimethacrylate (EGDMA) as functional monomers and cross-linker, respectively. MIP-coated QDs with an average diameter around 67 nm were obtained at the optimum conditions (the molar ratio of 1:8:20 of LMG, AM and EGDMA, 60 mL of acetonitrile, 28 h of polymerization time). The synchronous fluorescence of MIP-coated QDs was linearly quenched by LMG at concentrations from 0.1 to 20 μmol L −1 . Detection limit was 30 nmol L −1 (3 σ , n = 9) with spiked recoveries from 94.0% to 107.8% in fish samples. The results indicate that the method can be applied to the accurate and rapid detection of LMG residues in fish samples. [ABSTRACT FROM AUTHOR]

A fluorescent probe based on CdTe quantum dots (QDs) coated with molecularly imprinted polymers (MIPs) was fabricated for the determination of malachite green (MG) by the strategy of fluorescence resonance energy transfer (FRET). The MIP-coated QDs were synthesized through precipitation polymerization using acrylamide and ethylene glycol dimethacrylate as monomer and cross-linker, respectively. The optimum molar ratio of MG, monomer and cross-linker was 1:8:40 in 60 mL of acetonitrile, and the polymerization time was 28 h. The MIP-coated QDs, with an average diameter around 290 nm, showed excellent fluorescence emission in 500–700 nm at λ ex 370 nm. The probe exhibited fluorescence quenching response to MG selectively within only 5 min at the concentrations from 0.1 to 20 μmol L −1 . The fluorescent probe was successfully used to detect MG in water and fish samples with a detection limit of 0.059 μmol L −1 (3 σ , n = 9). The spiked recoveries, from 94.8% to 98.1% for water samples, and 98.1% to 106.2% for fish samples, respectively, indicated that the as-prepared MIP-coated QDs could be used as a fluorescent probe to detect MG rapidly in water and fish samples. [ABSTRACT FROM AUTHOR]

Abstract: Novel flexible parylene-based high-density electrode arrays have been developed for functional electrical stimulation in retinal and spinal cord prosthetics. These arrays are microfabricated according to a single-metal-layer process and a revolutionary dual-metal-layer process that promises to meet the needs of extremely high-density stimulation applications. While in many cases thin-film platinum electrodes in parylene C would be sufficient, high surface-area platinum electroplating has been shown to extend the lifetime of stimulated electrodes to more than 430 million pulses without failing. Iridium electrode arrays with higher charge delivery capacity have also been fabricated using a new high-temperature stabilized parylene variant, parylene HT. In addition, a new heat molding process has been implemented to conform electrode arrays to approximate the curvature of canine retinas, and a chronic implantation study of the mechanical effects of parylene-based electrode arrays on the retina over a 6-month follow-up period has provided excellent results. Retinal stimulation from these parylene-based electrode arrays in an isolated tiger salamander preparation was shown to be comparable to light stimulation in terms of generation of action potentials in the inner retina. Finally, electrode arrays have also been implanted and tested on the spinal cords of murine models, with the ultimate goal of facilitation of locomotion after spinal cord injury; these arrays provide a higher density and better spatial control of stimulation and recording than is typically possible using traditional fine-wire electrodes. Spinal cord stimulation typically elicited three muscle responses, an early (direct), a middle (monosynaptic), and a late (polysynaptic) response, classified based on latency after stimulation. Stimulation at different rostrocaudal levels of the cord yielded markedly different muscle responses, highlighting the need for such high-density arrays. [Copyright &y& Elsevier]