[Introduction] Transition metal chalcogenides (TMDCs) play an important role in chemistry, biosensing and tumor therapy, but TMDCs currently have challenges in the large-scale manufacturing of sensors and the clinical manifestations of tumor therapy. In response to this problem, Professor Zhang Han from Shenzhen University and Professor Chen Xiang from Nanjing University of Science and Technology (co-corresponding author) discussed and summarized the latest applications of TMDCs in the fields of biology, chemical sensors and tumor therapy, and compared different element compositions, phase structures, and microscopic shapes. The influence of morphology structure on material properties and the difference in application. It aims to evaluate the technological maturity of TMDCs in the field of sensing and tumor treatment, and proposes that an intelligent diagnosis and treatment system integrating sensing and treatment will become the future application direction of TMDCs. The paper "Transition Metal Dichalcogenides for Sensing and Oncotherapy: Status, Challenges, and Perspective" was published in the journal "Adv. Funct. Mater." 【Picture Guide】

Figure 1 Schematic diagram of the relationship between the elemental composition, structure and application of TMDCs 1. TMDCs materials and sensors TMDCs have the characteristics of large specific surface area, adjustable band gap, suitable electrical properties and low cytotoxicity, making them a good sensor preparation Choose materials. Factors affecting sensor performance include the element composition, phase structure and microscopic morphology of TMDCs. Element composition: Mainly affect the band gap, chemical stability, biocompatibility and molecular affinity. Among them, chalcogen elements are the leading factor in the biological toxicity of TMDCs, and also the main cause of degradation of TMDCs. Different transition metal elements have different affinity with probe molecules. Phase structure: mainly divided into semi-conducting 2H phase and metallic/semi-metallic 1T phase. High conductivity makes 1T-TMDCs an ideal choice for fluorescent biosensors, while 2H-TMDCs are commonly used in various transistor sensors. The study of 2H-1T phase transition opens up a new way for multi-type integrated biosensors. Microscopic morphology: TMDCs can be divided into two-dimensional flakes/thin films (lateral size >100 nm), nanosheets (NSs, <100 nm), nanodots (NDs), nanofibers (NFs) and nanorods (NRs). In most cases, the shape of TMDCs will determine the sensor structure design. Figure 2 Comparison of performance of TMDCs fluorescence sensors with different elements (ac) and phase structure (df) 2. Biological detection: TMDCs sensors with different structures TMDCs nanosheets and nanodots are small in size and can be uniformly dispersed in a solution or adsorbed on a sensing platform , Can also be combined with fibrous or rod-shaped materials to construct sensors, which are more suitable for electrochemical, fluorescence, chemiluminescence and colorimetric biosensors. From the sensor structure can be collectively referred to as Nanoscale TMDC-Based Transducing Component Biosensors (Nanoscale TMDC-Based Transducing Component Biosensors). Figure 3 TMDCs sensor based on nano-transducer unit (ab) WS2 nanofiber sensor; (c) MoS2 nanorod sensor charge transfer mechanism; (de) WS2 nanosheet sensor Figure 4 The influence of TMDCs morphology on device structure and sensing applications In FET Biosensors (FET Biosensors), two-dimensional sheet/film TMDCs are often used, and the lateral size of the material has reached the millimeter or even centimeter level. The sensor has higher sensitivity, lower detection limit (LOD) and response time. However, the micro-scale structure of the complex unit makes its manufacturing cost high and is susceptible to external interference. Figure 5 (ac) MoS2 FET sensor for amino acid detection; (de) MoS2 FET sensor cycle biological detection process principle diagram and continuous measurement of St response signal 3. TMDCs tumor treatment Figure 6 TMDCs single and combined treatment of tumors TMDCs due to their With high biocompatibility, stimulus responsiveness and inherent therapeutic effect, it is very suitable for a variety of tumor treatments and bioimaging. Monotherapy mainly includes photothermal therapy (PTT), photodynamic therapy (PDT), gene therapy (GT), immunotherapy (IT), chemotherapy (cT), etc. Based on TMDCs as photothermal/photoacoustic inducers and drug carriers, targeted release of stimulus-responsive drugs and imaging-guided therapy can be achieved. Due to the large heterogeneity of tumor types, pathological grades, aggressiveness and tissue/organs, combined therapy combining the advantages of multiple treatment methods is used to improve cancer treatment. Image-guided treatment can avoid normal tissue damage and improve the treatment effect. Therefore, TMDCs materials with imaging capabilities are more popular.

Figure 7 PCT nano diagnosis and treatment platform with different targeted modifiers Figure 8 The effect of different tumor treatment methods (single, double, triple therapy) Figure 9 Multi-modal imaging guided therapy based on TMDCs Figure 10 Practical application (a) for tumor PDT’s wireless metronome; (b) Frictional nano-generator used to control drug release. Figure 11 Prospects for the application of TMDCs [Summary] In summary, in recent years, a variety of wearable and biodegradable based on TMDCs have been developed Biosensors can evaluate key physiological indicators such as temperature, electric potential, blood pressure, O2 content and hormone levels. Next-generation smart biosensors should be able to simultaneously detect multiple interrelated target molecules, and then read these molecules through integrated logic circuits for rapid diagnosis. Future research on tumor therapy based on TMDCs should focus on the following aspects: 1. Accurate targeting and controllable therapeutic dose; 2. Controllable treatment progress and prognosis; 3. Diversified platforms that can treat multiple tumors simultaneously ; 4. Improve biodegradability to avoid potential long-term toxicity. Integrating biosensing and treatment into a diagnosis-treatment integration can greatly broaden the biomedical applications of TMDCs. Dr. Wang Lude from Shenzhen University, many from Nanjing University of Science and Technology, and Dr. Jiang Lianfu are the co-first authors of the paper. The corresponding authors of this paper are Professor Zhang Han from Shenzhen University and Professor Chen Xiang from Nanjing University of Science and Technology. Literature link: