Microcosmic 3D hierarchical structural design has proved to be an effective strategy to obtain high-performance microwave absorbers, although the treatments to low-dimensional cells in monolithic framework are usually based on semiempirical rules. In this work, a hierarchical carbon fiber (CF)@MXene@MoS 2 (CMM) core-sheath synergistic structure with tunable and efficient microwave absorption (MA) properties is fabricated by introducing self-assembled Ti 3 C 2 T x MXene on the surface of CF and subsequent anchoring of MoS 2. By the synergistic effects from the MXene sheath increasing the conductive loss and MoS 2 at the outermost layer improving the impedance matching, the MA performance of CMM can be effectively regulated and optimized: the optimal reflection loss is −61.51 dB with a thickness of 3.5 mm and the maximum effective absorption bandwidth covers the whole Ku-band with 7.6 GHz at 2.1 mm. Meanwhile, the whole X-band absorption can also be achieved with specific MoS 2 loading at an optimized thickness.

Artificial photoresponsive nanochannels have attracted widespread attention because of their capacity to achieve ion transport through light modulation. Herein, a biosensor for ultrasensitive miRNA‐155 detection is devised based on molybdenum disulfide (MoS2) modified porous anodic aluminum oxide (AAO) photoresponsive nanochannels by atomic layer deposition (ALD). According to the optimized experimental results, when the cycles of ALD, the wavelength, and the power of the excitation laser are 70 cycles, 450 nm, and 80 mW, respectively, the most supreme photocurrent performance of these photoresponsive nanochannels are obtained. AAO nanochannels modified with MoS2 can work as a photoelectrochemical (PEC) biosensor by generating photoexcitation current; what is more, the high channel density in AAO can magnify the ion current signal response effectively by aggrandizing the flux of electroactive species. By using AAO photoresponsive nanochannels with an average diameter of 150 nm as PEC biosensor, an ultrasensitive detection record ranging from 0.01 fM to 0.01 nM with a detection limit of 3 aM can be achieved. This work not only proposes a simple method for manufacturing semiconductor photoresponsive nanochannels, but also exhibits great potential in the ultrasensitive detection of biomolecules.

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Cancer has become a major killer threatening human health in today's society, and surface enhanced Raman spectroscopy (SERS) may provide a competitive choice for the sensitive detection of cancer‐related miRNAs. In this work, a synergistic calibrated SERS strategy based on MXene/molybdenum disulfide (MoS2)@Au nanoparticles (AuNPs) with controllable morphology is suggested for the ultrasensitive detection of miRNA‐182 by selecting the average intensity of its three own characteristic Raman peaks (at 382 cm−1 and 402 cm−1 corresponding to MoS2 and at 611 cm−1 corresponding to MXene) as a benchmark instead of additional beacon molecules. The linear goodness of fit (the determination coefficient R2) for this strategy is available in amounts up to 0.9995, which is significantly higher than that of single or double peak calibrated case, and thus improves the detection accuracy dramatically. Meanwhile, vertical MoS2 nanosheets anchored on layered MXene can provide uniformly ordered sites for accommodating suitably sized AuNPs as “hot spots” with controllable particle gap of 2.2 nm, resulting in the maximum amplified SERS signal at 1362 cm−1 generated by hairpin probe DNA with Cy5. A linear detection window from 10 am to 1 nm with an ultralow detection limit of 6.61 am for miRNA‐182 is achieved.

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