Dual-signaling and ultrasensitive detection for PCT based on the photoelectric and electrocatalytic hydrogen evolution signals of Pt/Mo-CoFeS

Few study has been carried out on the construction of immunesensors utilized the photoelectric and catalytic signal of nanomaterial. Here, a dual-signal electrochemical immunosensor was constructed for procalcitonin (PCT) detection based on the excellent photoelectric and hydrogen evolution performance of molybdenum-doped cobalt-iron sulfur nanosheets modified by platinum nanoparticles (Pt/Mo-CoFeS). Due to the electronic structure regulation between Pt and Mo-CoFeS, Pt/Mo-CoFeS exhibits superior photoelectric and hydrogen evolution performance compared to single Mo-CoFeS, which improved the sensitivity of the electrochemical immunosensor. Furthermore, the presence of Pt improves surface area and biocompatibility, achieving more antibodies loading and signal amplification. The linear range of PCT detection are 0.002-20 ng mL-1 and 0.002-50 ng mL-1, the detection limits are 0.0015 and 0.0012 ng mL-1. In addition, this electrochemical immunosensor was applied to the PCT analysis in human serum samples with high recoveries. F-test and t-test show that there is no significant difference in the test results between the HER and photoelectric signals, the mutual verification between above two signals can effectively improve the accuracy of detection result.

Schottky barrier height engineering on MoS2 field-effect transistors using a polymer surface modifier on a contact electrode

Two-dimensional (2D) materials are highly sought after for their superior semiconducting properties, making them promising candidates for next-generation electronic and optoelectronic devices. Transition-metal dichalcogenides (TMDCs), such as molybdenum disulfide (MoS₂) and tungsten diselenide (WSe₂), are promising alternative 2D materials. However, the devices based on these materials experience performance deterioration due to the formation of a Schottky barrier between metal contacts and semiconducting TMDCs. Here, we performed experiments to reduce the Schottky barrier height of MoS₂ field-effect transistors (FETs) by lowering the work function (Ф_m = E_vacuum - E_F,metal) of the contact metal. We chose polyethylenimine (PEI), a polymer containing simple aliphatic amine groups (-NH₂), as a surface modifier of the Au (Ф_Au = 5.10 eV) contact metal. PEI is a well-known surface modifier that lowers the work function of various conductors such as metals and conducting polymers. Such surface modifiers have thus far been utilized in organic-based devices, including organic light-emitting diodes, organic solar cells, and organic thin-film transistors. In this study, we used the simple PEI coating to tune the work function of the contact electrodes of MoS₂ FETs. The proposed method is rapid, easy to implement under ambient conditions, and effectively reduces the Schottky barrier height. We expect this simple and effective method to be widely used in large-area electronics and optoelectronics due to its numerous advantages.

Dual energy imaging in cardiothoracic pathologies: A primer for radiologists and clinicians

Recent advances in dual-energy imaging techniques, dual-energy subtraction radiography (DESR) and dual-energy CT (DECT), offer new and useful additional information to conventional imaging, thus improving assessment of cardiothoracic abnormalities. DESR facilitates detection and characterization of pulmonary nodules. Other advantages of DESR include better depiction of pleural, lung parenchymal, airway and chest wall abnormalities, detection of foreign bodies and indwelling devices, improved visualization of cardiac and coronary artery calcifications helping in risk stratification of coronary artery disease, and diagnosing conditions like constrictive pericarditis and valvular stenosis. Commercially available DECT approaches are classified into emission based (dual rotation/spin, dual source, rapid kilovoltage switching and split beam) and detector-based (dual layer) systems. DECT provide several specialized image reconstructions. Virtual non-contrast images (VNC) allow for radiation dose reduction by obviating need for true non contrast images, low energy virtual mono-energetic images (VMI) boost contrast enhancement and help in salvaging otherwise non-diagnostic vascular studies, high energy VMI reduce beam hardening artifacts from metallic hardware or dense contrast material, and iodine density images allow quantitative and qualitative assessment of enhancement/iodine distribution. The large amount of data generated by DECT can affect interpreting physician efficiency but also limit clinical adoption of the technology. Optimization of the existing workflow and streamlining the integration between post-processing software and picture archiving and communication system (PACS) is therefore warranted.

Ultrasensitive label- and amplification-free photoelectric protocols based on sandwiched layer-by-layer plasmonic nanocomposite films for the detection of alpha-fetoprotein

A label- and amplification-free photoelectric immunosensor based on well-defined layer-by-layer sandwich-structured AuNP/TNW/AuNP composite is proposed for direct and ultrasensitive detection of α-fetoprotein (AFP). The AuNP/TNW/AuNP composite is produced by assembling an Au nanoparticle underlayer and anatase TiO₂ nanowires (TNW) onto the FTO substrate, followed by decorating Au nanoparticles onto the TNW surface, through a simple sputtering and hydrothermal process. The resulting AuNP/TNW/AuNP electrode exhibits a 14-fold and 2-fold enhancement in photocurrent density under simulated sunlight compared with that of bare TNW and AuNP/TNW, respectively, which benefits from the SPR-induced photoabsorption increment and charge separation improvement in Au nanoparticle and interfacial charge transfer promotion at the TiO₂/substrate interface in the Au underlayer. As a proof of concept, the AFP antigen can be quantitatively detected by the proposed AuNP/TNW/AuNP coupled with anti-AFP through the analysis of the photocurrent change. This novel AFP photoelectric immunosensor exhibited sensitive detection of AFP with an ultrahigh sensitivity of 0.001 ng mL^-1 and good specific selectivity. Moreover, the practical determination of AFP in human serum is also investigated, demonstrating its applicability and potential attraction for clinical tests and disease diagnosis.

Cerium oxide nanoparticles: influence of the high-Z component revealed on radioresistant 9L cell survival under X-ray irradiation

This article pioneers a study into the influence of the high-Z component of nanoparticles on the efficacy of radioprotection some nanoparticles offer to exposed cells irradiated with X-rays. We reveal a significant decrease in the radioprotection efficacy for cells exposed to CeO2 nanoparticles and irradiated with 10 MV and 150 kVp X-rays. In addition, analysis of the 150 kVp survival curve data indicates a change in radiation quality, becoming more lethal for irradiated cells exposed to CeO2 nanoparticles. We attribute the change in efficacy to an increase in high linear energy transfer Auger electron production at 150 kVp which counterbalances the CeO2 nanoparticle radioprotection capability and locally changes the radiation quality. This study highlights an interesting phenomenon that must be considered if radiation protection drugs for use in radiotherapy are developed based on CeO2 nanoparticles.

FROM THE CLINICAL EDITOR

CeO2 nanoparticles are thought to offer radioprotection; however, this study reveals significant decrease in the radioprotection efficacy for cells exposed to CeO2 nanoparticles and irradiated with 10 MV and 150 kVp X-rays. This phenomenon must be considered when developing radiation protection drugs based on CeO2 nanoparticles.