Perovskite quantum dots (PQDs) have attracted much attention in the field of photoelectrochemical (PEC) sensors owing to their superb optical properties and efficient charge transport, but the ...inherent poor stability severely hinders their PEC applications. Herein, hydrolysis‐resistant CsPbBr3/reduced graphene oxide nanoscrolls (CsPbBr3/rGO NSs) are obtained by solvent‐assisted self‐rolling process toward water‐stable PEC sensors. CsPbBr3 QDs embedded in rGO nanosheets can be prevented from water since the multilayer rGO shell layers, which maintains excellent optical properties. On account of strong interfacial interactions, rGO nanosheets are crimped spontaneously with CsPbBr3 QDs, which offer access to superb structural and long‐term storage stability. Moreover, appropriate band alignment and ultrafast interfacial carrier transfer enable CsPbBr3/rGO NSs to exhibit greatly enhanced anode photocurrent response for subsequent PEC sensing. As a demonstration, the molecular imprinted PEC sensors for two kinds of mycotoxins (aflatoxin B1 or ochratoxin A) presents an ultra‐high sensitivity and good anti‐interference ability. Significantly, this work provides an inspirable and convenient route for hydrolysis‐resistant PQDs‐based optoelectronic and photoelectrocatalytic applications in aqueous ambience.
Water‐stable CsPbBr3/reduced graphene oxide nanoscrolls (CsPbBr3/rGO NSs) are successfully achieved via rGO self‐rolling and CsPbBr3 encapsulation, appropriate band alignment and ultrafast interfacial carrier transfer enable CsPbBr3/rGO NSs to exhibit greatly enhanced anode photocurrent response for subsequent photoelectrochemical sensing. This work provides an inspirable and convenient strategy for hydrolysis‐resistant perovskite‐based further applications in aqueous ambience.
Existing methods offer little direct and real‐time information about stretch‐triggered biochemical responses during cell mechanotransduction. A novel stretchable electrochemical sensor is reported ...that takes advantage of a hierarchical percolation network of carbon nanotubes and gold nanotubes (CNT‐AuNT). This hybrid nanostructure provides the sensor with excellent time‐reproducible mechanical and electrochemical performances while granting very good cellular compatibility, making it perfectly apt to induce and monitor simultaneously transient biochemical signals. This is validated by monitoring stretch‐induced transient release of small signaling molecules by both endothelial and epithelial cells cultured on this sensor and submitted to stretching strains of different intensities. This work demonstrates that the hybrid CNT‐AuNT platform offers a versatile and highly sensitive way to characterize and quantify short‐time mechanotransduction responses.
Cell stretching: A stretchable electrochemical sensor with excellent mechanical and electrochemical behavior and very good cellular compatibility has been developed. Transient biochemical signals during cell mechanotransduction can be induced and monitored in real time. This work offers a powerful platform to characterize and quantify mechanotransduction responses from mechanically sensitive cells.
CuO/BiOCl-based electrode made AFB1 efficiently photoelectrocatalytic degraded.
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•CuO/BiOCl composites were gained by in-situ growth of CuO on BiOCl surface.•The heterostructured ...CuO/BiOCl displayed greatly enhanced PEC response.•A CuO/BiOCl-based PEC biosensor was constructed for ultrasensitive AFB1 detection.
Aflatoxin B1 (AFB1) exposure often causes serious food safety problems and illnesses in humans and animals even at extremely low content. Therefore, ultrasensitive detection and effective degradation of AFB1 is vitally significant. Photoelectrochemical (PEC) approach has been widely applied in sensing and catalysis fields. For achieving robust PEC performance, exploring highly photoactive semiconductor materials is critical. Herein, we constructed a novel and dual-functional copper oxide/bismuth oxychloride (CuO/BiOCl) composite by in-situ growth of CuO on BiOCl surface. The photo-absorption region of CuO/BiOCl was efficaciously broadened from UV to visible range, making for enhanced light harvest. Meanwhile, the p-n heterostructure in CuO/BiOCl clarified that the formed built-in internal electric field could accelerate band-band transfer of carriers. Driven by this, PEC response of CuO/BiOCl was greatly boosted comparing with that of pure CuO or BiOCl. Further combing with the specific aptamer, a favorable CuO/BiOCl-based PEC biosensor was fabricated for AFB1 detection with ultra-sensitivity (detection limit of 0.07 pg mL−1) and satisfactory recoveries (96.4% ∼ 105.7%) in real maize samples. Subsequently, under light irradiation and suitable bias voltage, a degradation rate of ∼81.3% was facilely attained for 5.0 µg mL−1 AFB1, indicating excellent photoelectrocatalytic activity of CuO/BiOCl material. The catalytic mechanism and the main product of AFB1 degradation were analyzed. Taken together, the heterostructured CuO/BiOCl-based PEC assay provides a potential way for monitoring and controlling the AFB1 contamination in the food security areas.
Electrochemiluminescence (ECL) nanomaterials are usually deposited compactly on the surface of electrodes, which may cause poor mass transfer of reactants, thereby resulting in low ECL efficiency. In ...this work, we developed a novel kind of luminescent material denoted as C-Au-luminol nanospheres (C-Au-Lum NSs) by high dispersion of luminophores on porous carbon nanospheres (PCNSs). C-Au-Lum NSs were facilely prepared by the in situ reduction of chloroauric acid with the luminescent reagent luminol (Lum) on the nano-pores of PCNSs. Plenty of luminescent Au-Lum NPs were dispersedly concentrated inside the numerous pores and hollow interiors of PCNSs, effectively increasing the mass transfer of reagents and accelerating the electron transport inside the porous nanospheres. This greatly improved the availability of luminophores and endowed C-Au-Lum NSs with excellent ECL emission. After further integrating with enzymatic circulation and strand displacement, an ultrasensitive ECL biosensor was achieved for the ultrasensitive detection of an important tumor biomarker, mucin1. The logarithmically linear range from 0.1 pg mL-1 to 1 ng mL-1 with the detection limit of 47.6 fg mL-1 (S/N = 3) was achieved, demonstrating the superior performance of C-Au-Lum NSs. This work would provide new ideas for the construction of high-performance ECL sensing platforms for diverse applications.
Electrochemiluminescence (ECL) detection has attracted increasing attention as a promising analytical approach. A considerable number of studies showed that ECL intensity can be definitely improved ...by resonance energy transfer (RET), while the RET efficiency is strongly dependent on the distance between exited donors and acceptors. Herein we disclose for the first time a highly enhanced RET strategy to promote the energy transfer efficiency by coencapsulating the donor (Ru(bpy)32+)/acceptor (CdTe quantum dots, CdTe QDs) pairs into a silica nanosphere. Plenty of Ru(bpy)32+ and CdTe QDs closely packed inside a single nanosphere greatly shortens the electron-transfer path and increases the RET probability, therefore significantly enhancing the luminous efficiency. Further combining with molecularly imprinting technique, we develop a novel ECL sensor for ultrasensitive and highly selective detection of target molecules. Proof of concept experiments showed that extremely low detection limits of subfg/mL (S/N = 3) with broad linear ranges (fg/mL to ng/mL) could be obtained for detection of two kinds of mycotoxins (α-ergocryptine and ochratoxin A) that are recognized as potential health hazards at very low concentrations. This strategy combining enhanced RET system and molecularly imprinting technique, represents a versatile ECL platform toward low-cost, rapid, ultrasensitive, and highly selective detection of target molecules in diverse applications.
Since aggregation-induced electrochemiluminescence (AIECL) combined the merits of aggregation-induced emission (AIE) and electrochemiluminescence (ECL), it has become a research hotspot recently. ...Herein, novel kinds of functional metal–organic frameworks (MOFs) with strong AIECL were reported through doping tetraphenylethylene (TPE) into UiO-66. Due to the porosity and highly ordered topological structure that caused the confinement effect of MOFs, the molecular motion of TPE was effectively limited within UiO-66, resulting in strong AIE. Meanwhile, the large specific surface area and porous structure of UiO-66 allowed TPE to react with coreactants more effectively, which was beneficial to ECL. Thus, the TPE-functionalized UiO-66 (TPE-UiO-66) showed excellent AIECL performance surprisingly. Inspired by this, a multiple convertible ECL resonance energy transfer (ECL-RET) system was constructed through a DNA Y structure that regulated the distance between the energy donor (TPE-UiO-66) and different energy acceptors (gold nanoparticles and Adriamycin). Furthermore, an ultrasensitive ECL biosensor for the detection of Mucin 1 (MUC1) was developed through the introduction of the novel ECL-RET system. In the presence of MUC1, the DNA Y structure was constructed, keeping the gold nanoparticles (AuNPs) away from TPE-UiO-66. Then, Adriamycin (Dox) could be embedded in the DNA Y structure and act as an energy acceptor to receive the energy of TPE-UiO-66, which made the biosensor produce a strong ECL response. As expected, the developed ECL biosensor exhibited superior detection performance for MUC1. This work provided a novel way to realize AIECL and board the application of AIECL in analytical chemistry.
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•MAPB QDs@SiO2 nanocomposites are synthesized by a one-pot procedure.•MAPB QDs@SiO2 shows greatly enhanced ECL response in an organic electrolyte.•Ultrasensitive molecularly imprinted ...ECL sensors are constructed to detect AFB1.•This sensing platform is successfully applied for AFB1 assay in real corn oil.
Mycotoxins contamination, especially aflatoxin B1 (AFB1) in edible oils, is a health hazard. Therefore, AFB1 trace analysis methods are urgently needed. Electrochemiluminescence (ECL) is a popular sensing method because of its low background interference and high sensitivity. However, existing ECL assays for AFB1 detection are based on aqueous rather than oil systems. Herein, we report a CH3NH3PbBr3 quantum dots (MAPB QDs)@SiO2-based ECL sensor for AFB1 quantification in corn oil using an organic electrolyte. The luminophore loading and stability of the MAPB QDs@SiO2 particles were significantly improved compared to those of bulky MAPB materials, resulting in an enhanced ECL response. Further, exploiting molecular imprinting technology, an ECL sensor for AFB1 detection with an ultra-low detection limit of 8.5 fg/mL was prepared. The reliability of the sensor was confirmed by comparable recoveries of corn oil samples with those obtained by high-performance liquid chromatography, indicating its potential for food safety evaluation.
A reliable and practical Reformatsky reaction of ethyl iodide acetate with ketones for the synthesis of chiral β‐hydroxyl carbonyl compounds in good yields and excellent enantioselectivities is ...presented. A readily available dihydroindole derivative was used as chiral catalyst, ethyl iodide acetate was the nucleophile, and Me2Zn was the zinc source. The presence of air was found to be essential for the efficient construction of new carbon–carbon bonds through a radical pathway.
Asymmetric Reformatsky reaction of ethyl iodide acetate with ketones was realized via the initiation of Me2Zn and the proper stereocontrol of the chiral Zn‐indolinylmethanol complex. Various chiral β‐hydroxyl carbonyl compounds were obtained in good yields and excellent enantioselectivities (up to 97 % ee).
