Recently, flexible capacitive pressure sensors have received significant attention in the field of wearable electronics. The high sensitivity over a wide linear range combined with long-term durability is a critical requirement for the fabrication of reliable pressure sensors for versatile applications. Herein, we propose a special approach to enhance the sensitivity and linearity range of a capacitive pressure sensor by fabricating a hybrid ionic nanofibrous membrane as a sensing layer composed of Ti3C2T x MXene and an ionic salt of lithium sulfonamides in a poly­(vinyl alcohol) elastomer matrix. The reversible ion pumping triggered by a hydrogen bond in the hybrid sensing layer leads to high sensitivities of 5.5 and 1.5 kPa–1 in the wide linear ranges of 0–30 and 30–250 kPa, respectively, and a fast response time of 70.4 ms. In addition, the fabricated sensor exhibits a minimum detection limit of 2 Pa and high durability over 20 000 continuous cycles even under a high pressure of 45 kPa. These results indicate that the proposed sensor can be potentially used in mobile medical monitoring devices and next-generation artificial e-skin.

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A flexible electrochemical heavy metal sensor based on a gold (Au) electrode modified with layer-by-layer (LBL) assembly of titanium carbide (Ti3C2T x ) and multiwalled carbon nanotubes (MWNTs) nanocomposites was successfully fabricated for the detection of copper (Cu) and zinc (Zn) ions. An LBL drop-coating process was adopted to modify the surface of Au electrodes with Ti3C2T x /MWNTs treated via ultrasonication to fabricate this novel nanocomposite electrode. In addition, an in situ simultaneous deposition of “green metal” antimony (Sb) and target analytes was performed to improve the detection performance further. The electrochemical measurement was realized using square wave anodic stripping voltammetry (SWASV). Moreover, the fabricated sensor exhibited excellent detection performance under the optimal experimental conditions. The detection limits for Cu and Zn are as low as 0.1 and 1.5 ppb, respectively. Furthermore, Cu and Zn ions were successfully detected in biofluids, that is, urine and sweat, in a wide range of concentration (urine Cu: 10–500 ppb; urine Zn: 200–600 ppb; sweat Cu: 300–1500 ppb; and sweat Zn: 500–1500 ppb). The fabricated flexible sensor also possesses other advantages of ultra-repeatability and excellent stability. Thus, these advantages provide a great possibility for the noninvasive smart monitoring of heavy metals in the future.

Heteroatom-incorporated graphene represents a prominent family of materials utilized as active electrodes for multimodal sensing and energy storage applications. Herein, a novel polyaziridine-encapsulated phosphorene (PEP)incorporated flexible 3D porous graphene (3DPG) electrode is developed using facile, cost-effective laser writing, and drop-casting techniques. Owing to the excellent electrochemical characteristics and surface functionality of the highly stable PEP, the fabricated PEP/3DPG is evaluated as a potential electrode for immunosensing, electrocardiogram (ECG) recording, and microsupercapacitors (MSCs). Under optimized conditions, the produced PEP/3DPG-based carcinoembryonic immunosensor exhibits linear ranges of 0.1-700 pg mL −1 and 1-100 ng mL −1 with a detection limit of 0.34 pg mL −1 and high selectivity. The finger touch-based ECG sensor demonstrates a relatively low and stable impedance at the skin-electrode interface; therefore, the signal-to-noise ratio of the ECG signal received from the fabricated sensor (13.5 dB) is comparable to that of conventional Ag/AgCl electrodes (13.9 dB). Besides, the highest areal capacitance of the prepared MSC reached a magnitude of 16.94 mF cm −2 , which is six times higher than that of a nondoped 3DPG-based MSC. These results demonstrate the effectiveness of the described fabrication procedure and the high utilization potential of the encapsulated phosphorene-doped 3D graphene in multimodal applications.

A room-temperature metal-free method for generating highly unstable methyl radical was realized from the combination of PhI(OAc) 2 and 2-nitropropane, which provides an efficient approach to methylated phenanthridines and isoquinolines. The strategy was also extended to the generation of other alkyl radicals and a concise synthesis of Roxadustat.

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