1T-Phase molybdenum sulfide/cobalt oxide nanopillars hybrid nanostructure coupled with nitrogen-doped carbon thin-film as high efficiency electrocatalyst for oxygen evolution.

High efficient and durable catalysts are always needed to lower the kinetic barriers as well as prolong the service life associated with oxygen evolution reaction (OER). Herein, a sequential synthetic strategy is considered to prepare a hierarchical nanostructure, in which each component can be configured to achieve their full potential so that endows the resulting nanocatalyst a good overall performance. In order to realize this, well-organized cobalt oxide (Co3O4) nanopillars are firstly grown onto ultrathin 1T-molybdenum sulfide (1T-MoS2) to obtain high surface area electrocatalyst, providing electron transfer pathways and structural stability. After that, zeolitic imidazolate framework-67 (ZIF-67) derived carbonization film is further in situ deposited on the surface of nanopillars to generate plentiful active sites, thereby accelerating OER kinetics. Based on the combination of different components, the electron transfer capability, catalytic activity and durability are optimized and fully implemented. The obtained nanocatalyst (defined as 1T-MoS2/Co3O4/CN) exhibits the superior OER catalytic ability with the overpotential of 202 mV and Tafel slope of 57 mV·dec-1 at 10 mA·cm-2 in 0.1 M KOH, and good durability with a minor chronoamperometric decay of 9.15 % after 60,000 s of polarization.

Phase-Regulated Sensing Mechanism of MoS2 Based Nanohybrids toward Point-of-Care Prostate Cancer Diagnosis.

Alpha-methylacyl-CoA racemase (AMACR) has been proven to be consistently overexpressed in prostate cancer epitheliums, and is expected to act as a positive biomarker for the diagnosis of prostate carcinoma in clinical practice. Here, a strategy for specific determination of AMACR in real human serum by using an electrochemical microsensor system is presented. In order to implement the protocol, a self-organized nanohybrid consisting of metal nanopillars in a 2D MoS2 matrix is developed as material for the sensing interface. The testing signal outputs are strongly enhanced with the presence of the nanohybrids owing to that the metal pillars provide an efficient mass difussion and electron transfer path to the MoS2 film surface. Furthermore, the phase-regulated sensing mechanism over MoS2 is noticed and demonstrated by density functional theory calculation and experiments. The explored MoS2 based nanohybrids are employed for the fabrication of an electrochemical microsensor, presenting good linear relationship in both ng µL-1 and pg µL-1 ranges for AMACR quantification. The sampling analysis of human serum indicates that this microsensor has good diagnostic specificity and sensitivity toward AMACR. The proposed electrochemical microsensor system also demonstrates the advantages of convenience, cost-effectiveness, and disposability, resulting in a potential integrated microsystem for point-of-care prostate cancer diagnosis.

Detection of Lysyl Oxidase-Like 2 (LOXL2), a Biomarker of Metastasis from Breast Cancers Using Human Blood Samples.

Metastasis accounts for 90% of the mortality associated with breast cancer. Upregulated expression of members of the lysyl oxidase (LOX) family of secreted copper amine oxidases catalyzes the crosslinking of collagens and elastin in the extracellular matrix. LOXs are linked to the development and metastatic progression of breast cancers. Accordingly, aberrant expression of LOX-like 2 (LOXL2) is observed in poorly differentiated, high-grade tumors and is predictive of diseases recurrence, and for decreased overall patient survival. Therefore, LOXL2 expression may serve as a biomarker for breast cancer. Mechanistically, hydrogen peroxide is produced as a byproduct of LOXL2 when using an appropriate substrate, lysine. We exploited this chemistry to generate a revolutionary gold-based electrochemical biosensor capable of accurately detecting nanomolar quantities of LOXL2 in mouse blood, and in human blood samples. Two different sources of the blood samples obtained from breast cancer patients were used in this study indicating the applicability of detecting LOXL2 in breast cancers patients. Limited numbers of urine specimens from breast cancer patients were also tested. Collectively, all of these tests show the promise and potential of this biosensor for detecting LOXL2 as a surrogate biomarker of breast cancer. This work is described in WO 052962 A1 (2014).