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The structure diagram and detection mechanism of CsPbBr3/TDPA.

Silver-based organic frameworks with high ECL activity were synthesized and applied for the first time to construct an ECL sensor. The detection limit was as low as 66 fM for mercury ion concentration in water.

The composite PCN-222@CdSe was used to detect PNP.

The electrochemiluminescence and resonance energy transfer (ECL-RET) method was adopted to detect miRNAs, in which the two-dimensional Ti

Here, we proposed a ratiometric electrochemiluminescent (ECL) strategy in spatially multiplied ECL systems. By the specific recognition of hyaluronic acid with proteoglycan CD44 and epidermal growth factor with epidermal growth factor receptor on the cell surface, the cells were labelled with potential-resolved ECL probes, namely Ru(bpy)32+ and g-C3N4, respectively. The as-proposed cytosensor provides a multichannel ECL protocol to improve the throughput, which may push the application of ECL for the cellular immunoanalysis.

A novel photoelectrochemical (PEC) biosensor based on b-TiO

In this work, a potential-resolved electrochemiluminescence (ECL) method is developed and used for the apoptosis diagnosis at the single-cell level. The apoptosis of cells usually induces the decreasing expression of epidermal growth factor receptor (EGFR) and promotes phosphatidylserine (PS) eversion on the cell membrane. Here, Au@L012 and g-C3N4 as ECL probes are functionalized with epidermal growth factor (EGF) and peptide (PSBP) to recognize the EGFR and PS on the cell surface, respectively, showing two well-separated ECL signals during a potential scanning. Experimental results reveal that the relative ECL change of g-C3N4 and Au@L012 correlates with the degree of apoptosis, which provides an accurate way to investigate apoptosis without interference that solely changes EGFR or PS. With a homemade ECL microscopy, we simultaneously evaluate the EGFR and PS expression of abundant individual cells and, therefore, achieve the visualization analysis of the apoptosis rate for normal and cancer cell samples...

In this paper, hydrothermal method was used for the synthesis of SnO

Herein, a label-free photoelectrochemical immunosensor based on a g-C3N4/CdSe nanocomposite was established and applied to detect carcinoembryonic antigen (CEA). The prepared nanocomposite materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectrometer (FT-IR) and photoluminescence spectroscopy (PL). The results indicate that g-C3N4/CdSe nanocomposite materials were successfully synthesized. In a typical assembly process, the immunosensor was constructed by modifying a fluorine-doped tin oxide (FTO) electrode with poly dimethyl diallyl ammonium chloride (PDDA), the g-C3N4/CdSe nanocomposite, the anti-carcinoembryonic antigen antibody (Ab) and the blocking agent bovine serum albumin (BSA) successively. In the presence of CEA, the photocurrent signal of the prepared immunosensor decreased significantly. Accordingly, under the optimal conditions, a label-free photoelectrochemical immunosensor was established, and it exhibited excellent selectivity and repeatability for CEA detection. The detection limit was 0.21 ng mL-1, and the range was 10 ng mL-1-100 μg mL-1. Simultaneously, the immunosensor also provides a likely sensing device for detecting other protein targets, which is of great significance for early clinical diagnosis.

A novel enhanced photoelectrochemical (PEC) DNA biosensor, based on a compact heterojunction g-C3N4/MoS2 and co-sensitization effect with CdSe quantum dots (QDs), was first proposed for simple and accurate analysis of a short ssDNA. In this work, the g-C3N4/MoS2 was successfully synthesized and used as the electrode matrix material to construct PEC biosensor. 2D/2D heterojunction was formed between g-C3N4 and MoS2, which could promote the separation of photogenerated electron-hole pairs resulting in an enhanced photocurrent. In the presence of target DNA, CdSe QDs labeled reporter DNA was complementary pairing with target DNA which was specific recognized by capture DNA loading on self-assembled CdS QDs film, leading to close contact between CdSe QDs and g-C3N4/MoS2 modified electrode surface, thereby resulting in the enhanced photocurrent intensity due to the co-sensitization effect. Under the optimal operating conditions, the photoelectrochemical biosensor demonstrated favorable accuracy and could respond to 0.32 pM (S/N = 3) with a linear concentration range from 1.0 pM to 2.0 μM. Moreover, the proposed PEC DNA biosensor exhibits high sensitivity, excellent specificity, acceptable reproducibility and accuracy, showing a promising potential in DNA bioanalysis and other relative fields.

Herein, an ultra-sensitive photoelectrochemical biosensor based on Ti

Herein, an efficient photoelectrochemical (PEC) platform was constructed by a cosensitization strategy with a cascade energy level arrangement for the ultrasensitive evaluation of T4 polynucleotide kinase (T4 PNK). Based on CdSe quantum dots (QDs) with an extremely narrow bandgap, this cosensitization strategy offered a highly efficient sensitizer with a matching band-edge level of a ternary TiO2/g-C3N4/CdS nanocomposite. In this protocol, the ternary nanocomposite was first prepared to serve as the matrix to construct the PEC sensing platform. On the other hand, a well-designed hairpin DNA1 probe with 5'-hydroxyl termini was specifically phosphorylated by T4 PNK which would be selectively cleaved with lambda exonuclease (λ-Exo) outputting the 3'-thiol end ssDNA2. After tagged with CdSe QDs, ssDNA2 was captured by the complementary capture DNA3 on the electrode surface. As a result, CdSe QDs were in close contact with the ternary nanocomposite matrix, leading to an enhanced photocurrent response. Therefore, this proposed PEC platform displayed an analytical performance with a wide linear range from 0.0001 to 0.02 U mL-1 and a low detection limit down to 6.9 × 10-5 U mL-1. Moreover, this ternary nanocomposite-based platform exhibited excellent selectivity, good reproducibility, and remarkable storage stability, which shows great potential for T4 PNK detection and inhibitor screening.

In this paper, carboxylated C3N4 (g-C3N4-COOH) was prepared by a new method, and then combined with ZnSe quantum dots (QDs) through amide reaction to form g-C3N4-COOH/ZnSe nanocomposite and used for detecting kanamycin. The prepared g-C3N4-COOH/ZnSe nanocomposite was used as the subatrate of aptasensor. Then, the g-C3N4-COOH/ZnSe nanocomposite-modified electrode was incubated with aptamer DNA (NH2-DNA), after cholamine blocked the unbond sites of the electrode surface, the ferrocene-labled quenching probe (Fc-DNA) as electrochemiluminescence (ECL) signal quencher was incubated on the electrode surface through base complementation with aptamer DNA. In the absence of kanamycin, the ECL signal was quenched effectively by Fc-DNA. On the contrary, kanamycin was specifically bond with aptamer DNA, and Fc-DNA was detached from the aptasensor electrode surface because of the deformation of aptamer DNA, generating an effectively enhanced ECL signal. The aptasensor exhibited a wide detection range for detecting kanamycin (1.0 nM − 100 μM) with a low limit of detection (0.7982 nM). The prepared aptasensor displayed a stable and selective detection for kanamycin, and also provided a promising strategy for a variety of other protein target.

An ultrasensitive electrochemiluminescence biosensor was established based on the Zn-MOF/GO nanocomposite. Ag(I)-embedded DNA complexes were used as a signal amplification reagent. In this work, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and Zn

In this work, an electrochemiluminescence (ECL) biosensor was fabricated for the selective detection of vascular endothelial growth factor (VEGF

In situ detection of the expression level of cell-surface receptors has become a hotspot study in recent years. We propose in this manuscript a novel strategy for sensitive electrochemiluminescence (ECL) detection of glucose transporter 4 (GLUT4) on human skeletal muscle cells (HSMCs). Graphene hydrogel (GH) was selected to fabricate a permeable electrode with the purpose of overcoming the steric hindrance of cells on electrode, which leads to errors in the detection of cell-surface receptors. GLUT4 was labeled with carbon dots (CDs), which generate ECL emission at the interface between GH and cells, so about half the amount of GLUT4 expressed at the cell surface could be determined, which provided an accurate GLUT4 expression quantification. The prepared cytosensor exhibited good analytical performance for HSMC cells, ranging from 500 to 1.0 × 106 cells·mL-1, with a detection limit of 200 cells·mL-1. The average amount of GLUT4 per HSMC cell was calculated to be 1.88 × 105. Furthermore, GLUT4 on HSMC surface had a 2.3-fold increase under the action of insulin. This strategy is capable of evaluating the receptors on the cell surface, which may push the application of ECL for disease diagnosis.

Herein, an efficient photoelectrochemical (PEC) platform was constructed by a cosensitization strategy with a cascade energy level arrangement for the ultrasensitive evaluation of T4 polynucleotide kinase (T4 PNK). Based on CdSe quantum dots (QDs) with an extremely narrow bandgap, this cosensitization strategy offered a highly efficient sensitizer with a matching band-edge level of a ternary TiO

Single-cell imaging is essential for elucidating the biological mechanism of cell function because it accurately reveals the heterogeneity among cells. The electrochemiluminescence (ECL) microscopy technique has been considered a powerful tool to study cells because of its high throughput and zero cellular background light. However, since cells are immobilized on the electrode surface, the steric hindrance and the insulation from the cells make it difficult to obtain a luminous cell ECL image. To solve this problem, direct ECL imaging of a single cell was investigated and achieved on chitosan and nano-TiO2 modified fluoride-doped tin oxide conductive glass (FTO/TiO2/CS). The permeable chitosan film is not only favorable for cell immobilization but also increases the space between the bottom of cells and the electrode; thus, more ECL reagent can exist below the cells compared with the cells on a bare electrode, which guarantees the high sensitivity of quantitative analysis. The modification of nano-TiO2 strengthens the ECL visual signal in luminol solution and effectively improves the signal-to-noise ratio. The light intensity is correlated with the H2O2 concentration on FTO/TiO2/CS, which can be applied to analyze the H2O2 released from cells at the single-cell level. As far as we know, this is the first work to achieve cell ECL imaging without the steric hindrance effect of the cell, and it expands the applications of a modified electrode in visualization study.

Herein, we established a novel ultrasensitive photoelectrochemical biosensor for detecting urokinase-type plasminogen activator (u-PA), based on a g-C

A novel enhanced photoelectrochemical DNA sensor, based on a TiO

A film of perovskite-type LaFeO

The oxidation of formaldehyde in alkaline solution was studied by in situ rapid-scan time-resolved IR spectroelectrochemistry (RS-TR-FTIRS) method. In the potential range between −0.7 V and 0.2 V, the gem -diol anions were oxidized (according to the 2765 cm −1 of υ H O and 1034 cm −1 of υ CO downward IR bands) and the formate ions appeared (according to the 1588, 1357 cm −1 of the asymmetric and symmetric υ OCO and 1380 cm −1 of δ C H upward IR bands) in aqueous solution. It was also confirmed that gem -diol anion was oxidized (according to the 2026, 1034 cm −1 downward IR bands) to formate ions (according to the 1595, 1357, 1380 cm −1 upward IR bands) and water (according to the 3427 cm −1 of υ H O upward IR band) in heavy water solution. The results illustrated that formaldehyde formed gem -diol anion in alkaline solution and was absorbed on the electrode surface; then gem -diol anion was oxidized to formate ions and water.

We report a facile synthesis of spherical ZnS nanocrystals modified with dianion of 3-ferrocenyl-2-crotonic acid (FCA) from one-dimensional (1-D) coordination polymer. Zn(II) coordination polymer has been demonstrated as both precursor and template in the preparation and surface modifications of nanomaterials. Moreover, an ionic liquid 1-butyl-3-methylimidaz-olium tetrafluoroborate ([BMIM]BF4) solution system has been designed as an assisting template in this experiment. We demonstrate that the 1-D polymeric chain structure is an excellent template for synthesizing organized assemblies of ZnS nanocrystals at low temperatures and ambient atmosphere. From a combination of X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM), the morphology of the synthesized nanocrystals is spherical and with diameters ranging from 40 to 60 nm. The nanocrystals were further examined by FT-IR and UV–visible absorption spectra. In all, we represent a general strategy which is not only environment friendly but also fast and seedless for the preparation of functional nanomaterials.

A novel chemical method has been developed for the preparation of crystalline nanotubes of silver selenide (Ag2Se). The method is based on the template-engaged synthesis in which the trigonal Se nanotubes as-prepared were used as template reagent. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), ultraviolet (UV) analysis, photoluminescence (PL) analysis, differential scanning calorimetric (DSC) analysis, and thermogravimetric (TG) analysis. Based on a series of experiments and characterizations, the formation mechanism of the Ag2Se nanotubes was proposed. Furthermore, the useful electrochemical behavior of the Ag2Se nanotubes was studied by the voltammetric technique.

Comparative studies were carried out by using electrochemistry and in-situ FTIR spectroelectrochemistry for nonlinear optical complexes, S-benzyl-N-(ferrocenyl-1-methyl-metylidene)-dithiocarbazate nickel (II)/cobalt (II) complexes (Ni(LSB)2/Co (LSB)2). The results indicated that Ni(LSB)2 involves two consecutive reversible one-electron oxidation steps, while Co(LSB)2 involves only one two-electron oxidation step. Ni(LSB)2 complex that has a square planar configuration exhibits a moderately strong electronic communication between the two-ferrocene moieties, taking place through the skeleton chain of the ligand due to the extensive electron delocalization in the whole molecule and leads to the appearance of a strong nu c-c vibration band at 1,453 cm-1 during the oxidation process, while Co(LSB)2 complex that has a tetrahedral configuration shows low electron delocalization and has two almost identical ferrocene moieties.