There has been an upsurge of green reductants for the preparation of graphene materials taking consideration of human health and the environment in recent years. In this paper, reduced graphene oxides (RGOs) were prepared by chemical reduction of graphene oxide (GO) with three green reductants, L-ascorbic acid (L-AA), D-glucose (D-GLC) and tea polyphenol (TP), and comparatively characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectra, Raman spectra and electrical conductivity analysis. Results showed that all these three reductants were effective to remove oxygen-containing functional groups in GO and restore the electrical conductivity of the obtained RGO. The RGO sample with L-ascorbic acid as a reductant and reduced with the existence of ammonia had the highest electrical conductivity (9.8 S·cm-1) among all the obtained RGO samples. The mechanisms regarding to the reduction of GO and the dispersion of RGO in water were also proposed. It is the good dispersibility of reduced graphene oxide in water that will facilitate its further use in composite materials and conductive ink.

Multiwalled carbon nanotubes (MWCNTs) were used to convert radome materials to microwave absorbing materials. Dense MWCNT-fused silica composites were prepared by hot-pressing technique. The composites exhibit high complex permittivities at X-band frequencies, depending on the content of MWCNTs. The value of the loss tangent increases three orders over pure fused silica only by incorporating 2.5vol% MWCNTs into the composites. The average magnitude of microwave transmission reaches −33dB at 11–12GHz in the 10vol% MWCNT-fused silica composites, which indicates the composites have excellent microwave attenuation properties. The attenuation properties mainly originate from the electric loss of MWCNTs by the motion of conducting electrons.

Generally, photoanode-based photoelectrochemical immunoassay possesses obvious photocurrent response and lower detection limit for ideal sample detection, but it has the inherent imperfection of poor anti-interference capability for real sample detection. Photocathode-based immunoassay can well avoid the intrinsic drawback of photoanode-based immunoassay, but it has low photocurrent response resulting in less good sensitivity. Herein, a promising new cathode photoelectrochemical immunosensing platform integrating photocathode with photoanode was reported for accurate and sensitive detection of biomarkers. In this proposal, prostate-specific antigen (PSA, Ag) was chosen as a model of target analyte to exhibit the analytical performances of this platform. TiO/CdS:Mn hybrid structure modified indium-tin oxide (ITO) electrode served as photoanode, whereas CuInS microflowers modified ITO electrode was selected as photocathode. The transducer elements of PSA antibody (Ab) were modified on photocathode to fabricate a label-free cathode immunosensing electrode. The proposed immunosensing platform possesses two distinct advantages simultaneously. First, it has good anti-interference capability for the detection of real biological samples, since the biorecognition events occurred on photocathode. Second, the photoelectrochemical system owns evident photocurrent response and low detection limit for target Ag detection thanks to the introduction of the photoanode. Moreover, the proposed immunosensing platform also exhibits good specificity, reproducibility, and stability, and meanwhile it opens up a new horizon to construct other kinds of photoelectrochemical biosensors.

New tools for single‐cell interrogation enable deeper understanding of cellular heterogeneity and associated cellular behaviors and functions. Information of RNA expression in single cell could contribute to our knowledge of the genetic regulatory circuits and molecular mechanism of disease development. Although significant progresses have been made for intracellular RNA analysis, existing methods have a trade‐off between operational complexity and practical feasibility. We address this challenge by combining the ionic current rectification property of nanopipette reactor with duplex‐specific nuclease‐assisted hybridization chain reaction for signal amplification to realize a simple and practical intracellular nanosensor with minimal invasiveness, which enables single‐cell collection and electrochemical detection of intracellular RNA with cell‐context preservation. Systematic studies on differentiation of oncogenic miR‐10b expression levels in non‐malignant breast cells, metastatic breast cancer cells as well as non‐metastatic breast cancer cells were then realized by this nanotool accompanied by assessment of different drugs effects. This work has unveiled the ability of electrochemistry to probe intracellular RNA and opened new opportunities to study the gene expression and heterogeneous complexity under physiological conditions down to single‐cell level.