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In this work, we report a nanoscale multichannel closed bipolar electrode (BPE) array based on the poly(ethylene terephthalate) (PET) membrane for the first time. With our design, oxidants, coreactants, quenchers, and even biomarkers can be detected in a Ru(bpy)32+/TPA (tripropylamine) electrochemiluminescence (ECL) system. The multichannel PET membrane was etched according to our desire by NaOH, and then Au nanofibers were decorated in the inner region of the channel as a BPE array. Using ECL as a signal readout, a series of targets including TPA, Ru(bpy) 32+, dopamine, H2O2, alpha-fetoprotein (AFP), and carcino-embryonic antigen (CEA) can be detected with this device. The practical application of the proposed multichannel closed BPE array was verified in the detection of AFP and CEA in human serum with satisfying results. This kind of nanoscale device holds promising potential for multianalysis. More importantly, as the PET membrane used in this device can be etched with a desirable diameter (nano- to microscale) and different BPE array densities (ion tracks of 108/cm2, 106/cm2, 104/cm2), our design can be served as a useful platform for future advances in nanoscale bipolar electrochemistry. [ABSTRACT FROM AUTHOR]

In this work, we have developed a full-featured electrochemiluminescence (ECL) sensing platform based on a multichannel closed bipolar system. Owing to the three-channel and double-bipolar electrode (BPE) configuration, all the oxidants, reductants, or chemicals that are directly related to the ECL process can be detected in a single device, which greatly expanded the application range of the Ru(bpy)32+-TPA (tripropylamine) anodic ECL reaction. First of all, a more universal and accurate mechanism for all the bipolar systems was proposed by observing the reactions that occurred in the device with universal pH indicator and ITO BPEs. On the basis of that, Pt was electrodeposited onto all the ITO cathodes to improve the signal stability and construct the multifunctional ECL sensor. With this design, the determination of H2O2, ascorbic acid (AA), TPA, glucose, and blood sugar were achieved in a single device. More importantly, we have demonstrated that the constructed sensor array can be used as a high-throughput molecular keypad lock in the visual ECL experiment. This design therefore shows great promise in various fields. [ABSTRACT FROM AUTHOR]

In this work, a novel style of a microfluidic-based bipolar system with two-direction driving electrodes and dual-channel configuration was described for the first time, which could reach 100% current efficiency in theory. More importantly, the background signal from the integrated driving electrodes was completely eliminated, when this unique design was used to construct an electrochemiluminescence (ECL) sensing platform. First, universal pH indicator was employed to study the mechanism and demonstrate that this new bipolar system possessed 100% current efficiency theoretically. Then, the Ru(bpy)32+/TPrA ECL system was introduced to construct the dual-channel bipolar ECL sensing platform, and the results of visual ECL experiments proved that the background signals from the driving electrodes were completely dispelled with our design. To illustrate the promising applications of this dual-channel device, TPrA, dopamine (DA), H2O2, and K3Fe(CN)6 were detected as model targets under different principles. [ABSTRACT FROM AUTHOR]

Bimetallic nanoclusters (NCs) with superior performance to that of monometallic nanoclusters have attracted extensive research interest due to the synergetic effect of the two atoms. Inspired from the silver effect on the enhanced fluorescence intensity of Au NCs, a series of bovine serum albumin-protected Au-Ag bimetallic NCs were prepared by regulating the molar ratios of HAuCl4/AgNO3 and their electrochemiluminescence (ECL) property was investigated using triethylamine as co-reactant. Notably, multifold higher efficiency was achieved with Au-Ag bimetallic NCs in reference to the monometallic nanoclusters. Moreover, the doping of Ag atoms not only made the ECL emission of the Au NCs blue shift but also decreased the peak potential and onset potential, which provided an efficient and facile way to improve the ECL behavior. Based on the ECL quenching effect of Hg2+ toward Au-Ag bimetallic NCs via the formation of metallophilic bond, an ECL sensor for Hg2+ detection was proposed with good stability and high selectivity and sensitivity. These results indicated that the as-prepared Au-Ag bimetallic NCs with enhanced ECL properties can be served as an ideal luminescent material in sensing application. [ABSTRACT FROM AUTHOR]

Herein, a multifunctional nanoarchitecture has been developed by integrating the branched poly(ethylenimine) functionalized graphene/iron oxide hybrids (BGNs/Fe3O4) and luminol capped gold nanoparticles (luminol-AuNPs). The luminescent luminol-AuNPs as an electrochemiluminescence marker can be assembled on the nanocarrier of BGNs/Fe3O4 hybrids efficiently via the Au–N chemical bonds and electrostatic adsorption. Meanwhile, the multifunctional nanoarchitecture has been proved with excellent electron transfer, good stability, high emission intensity, etc. Furthermore, we successfully developed an ultrasensitive magnetically-controlled solid-state electrochemiluminescence (ECL) platform for label-free determination of HeLa cells using this multifunctional nanocomposite. Excellent performance of the magnetically-controlled ECL biosensing platform has been achieved including a high sensitivity for HeLa cells with a linear range from 20 to 1 × 104 cells/mL, good stability, and reproducibility. [ABSTRACT FROM AUTHOR]