The rational structural design of materials is an efficient strategy for optimizing the sensing properties of pressure sensors for electronic skins. Here, inspired by the arches of the foot, a novel Janus graphene film (JGF) with concave‐convex arch‐shaped microstructures on both surfaces is presented. Then, a polymer‐substrate‐free pressure sensor with a wide sensing range, fast response time, and good stability is fabricated using a face‐to‐face assembly method. Its special microstructures can effectively hinder the full contact of two face‐to‐face JGF electrodes and lead to a tunable pressure‐dependent contact area. Subtle pressure variations can be captured due to these special arch‐shaped microstructures. Hence, the JGF‐based pressure sensor could be used to monitor the vital signs of the human body such as human‐body motion, breathing, and arterial pulse. Stable epidermal pulse wave signals are detected, and a series of indices are extracted to assess arterial stiffness and vascular aging. Thanks to its low‐cost, simplified fabrication process, the pressure sensor exhibits great potential for monitoring health in real time and screening for arteriosclerotic disease.

Propyl gallate (PG) as one of the important synthetic antioxidants is widely used in the prevention of oxidative deterioration of oils during processing and storage. Determination of PG has received extensive concern because of its possible toxic effects on human health. Herein, we report a photoelectrochemical (PEC) sensor based on ZnO nanorods and MoS2 flakes with a vertically constructed p–n heterojunction. In this system, the n-type ZnO and p-type MoS2 heterostructures exhibited much better optoelectronic behaviors than their individual materials. Under an open circuit potential (zero potential) and visible light excitation (470 nm), the PEC sensor exhibited extraordinary response for PG determination, as well as excellent anti-inference properties and good reproducibility. The PEC sensor showed a wide linear range from 1.25 × 10–7 to 1.47 × 10–3 mol L–1 with a detection limit as low as 1.2 × 10–8 mol L–1. MoS2/ZnO heterostructure with proper band level between MoS2 and ZnO could make the photogenerated electrons and holes separated more easily, which eventually results in great improvement of sensitivity. On the other hand, formation of a five membered chelating ring structure of Zn­(II) with adjacent oxygen atoms of PG played significant roles for selective detection of PG. Moreover, the PEC sensor was successfully used for PG analysis in different samples of edible oils. It demonstrated the ability and reliability of the MoS2/ZnO-based PEC sensor for PG detection in real samples, which is beneficial for food quality monitoring and reducing the risk of overuse of PG in foods.