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This work reports an electrofluorochromic strategy on the basis of electric field control of fluorescent signal generation on bipolar electrodes (BPEs) for visualizing cancer cell surface glycoprotein (mucin 1). The device included two separate cells: anodic sensing cell and cathodic reporting cell, which were connected by a screen-printing electrode patterned on poly­(ethylene terephthalate) (PET) membrane. In the sensing cell, anti-MUC1 antibody immobilized on a chitosan-multiwalled carbon nanotube (CS-MWCNT)-modified anodic BPE channel was used for capturing mucin-1 (MUC1) or MCF-7 cancer cells. Then ferrocene (Fc)-labeled mucin 1 aptamers were introduced through hybridization. Under an applied voltage, the ferrocene was oxidized and the electroactive molecules of 1,4-benzoquinone (BQ) in the cathodic reporting cell were reduced according to electroneutrality. This produced a strongly basic 1,4-benzoquinone anion radical (BQ•–), which turned on the fluorescence of pH-responsive fluorescent molecules of (2-(2-(4-hydroxystyryl)-6-methyl-4H-pyran-4-ylidene)­malononitrile) (SPM) coexisting in the cathode reporting cell for both spectrophotometric detection and imaging. This strategy allowed sensitive detection of MUC1 at a concentration down to 10 fM and was capable of detecting a minimum of three MCF-7 cells. Furthermore, the amount of MUC1 on MCF-7 cells was calculated to be 6.02 × 104 molecules/cell. Our strategy also had the advantages of high temporal and spatial resolution, short response time, and high luminous contrast and is of great significance for human health and the promotion of life science development.

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Inspired by the promising applications of a closed bipolar electrodes (c-BPEs) system in electrochemiluminescence (ECL) detection of cell adhesion and disease-related biomarkers, here, a gold nanowires array-based c-BPEs system was constructed for cell surface protein detection. Regular and uniform gold nanowires array were prepared by intermittent potentiostatic deposition. Then, two poly-(dimethylsiloxane) (PDMS) chips with a hole diameter of 2 mm as a reservoir were placed at both sides of Au nanowires array to construct c-BPEs system. Thioninefunctionalized silicon dioxide nanoparticles conjugated to antibody (Ab2-Th@SiO 2 ) were used as the electrochemical probe, while [Ru(bpy) 3 ] 2+ -wrapped SiO 2 nanoparticles (Ru(II)@SiO 2 ) were employed as the ECL signal readout. Taking αfetoprotein (AFP) as model, the gold nanowires array-based c-BPEs system allowed sensitive detection of AFP at a linear range from 0.002 to 50.0 ng/mL and at least 6 living cells ascribing to the synergetic amplification effect at both sensing and reporting chambers. Besides, the amount of AFP expressed by HepG2 cells was calculated to be 6.71 pg/cell. The presented strategy with high sensitivity provided a promising and universal platform for the detection of other cancer cells and disease-related biomarkers (such as proteins, glycan, miRNA).

The low solubility of oxygen in solution is the main obstacle for the biodegradation of organic pollutants in wastewater. To address this problem, inspired by the degradation mechanism of aerobic bacteria toward organic pollutants, a novel photodegradation system was presented and operated by a heterojunction photocatalyst combining with a hydrophobic triphase interface, allowing oxygen to directly diffuse from the gas phase to active catalytic sites submersed in polluted solutions. Especially, the heterojunction photocatalyst was fabricated by graphitic carbon nitride nanosheets (C 3 N 4 NS) sensitized with 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin (TCPP). The resulting photocatalyst was coated on a certain part of the commercial superhydrophobic carbon paper (CP) and submersed in the polluted wastewater, while the other part of hydrophobic CP (without coating with C 3 N 4 -TCPP nanocomposite) was exposed to air to form a gas−liquid−solid tri-phase photodegradation system. With this system, the photodegradation rate was 10-fold higher than that of a conventional liquid/solid diphase system in oxygen-saturated solutions. This was, on one hand, due to the abundant oxygen on the surface of a photocatalyst coming from the fast and direct diffusion from the gas phase through the superhydrophobic nanoporous part of CP. On the other hand, the hybrid C 3 N 4 -TCPP nanocomposite enhanced the light absorption efficiency under simulated sunlight irradiation and restrained the recombination of photogenerated electron−hole. Moreover, the triphase photodegradation system was stable in aqueous solutions for a long time and can be reused almost without attenuation for five cycles, which provided a great potential to be utilized for practical wastewater treatment.