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A disposable screen-printed electrode modified with composite material of graphene aerogel, AuNPs, Nafion and PSA aptamer were fabricated for PSA detection. [Display omitted] • High-performance PSA detection based on SPE and electrochemical detection. • Introduce 3D graphene aerogel and AuNPs to highly boost detection sensitivity. • Highly sensitive and accurate detection of PSA with low LOD over 0.05 to 50 ng∙mL−1. Prostatic cancer threatens the lives and health of numerous male patients all over the world. As a single-chain glycoprotein, prostate specific antigen (PSA) can be used to perform prostate cancer screening. At present, there are still problems such as time-consuming and low sensitivity in hospital detection. At the same time, electrochemical immunosensor technology has received a lot of attention due to its benefits, including high sensitivity, good selectivity, low usage and cost, and so on. Electrocatalysts are typically used to build electrochemical immunosensors for signal amplification in the recent years to realize sensitive detection of cancer biomarkers such as PSA. In recent years, three-dimensional nanomaterials have been widely used in the study of electrocatalysts, but the study of the sensitivity for PSA detection is still very scarce. The present work reported the application of a 3D graphene aerogel(GA)/AuNPs/Nafion electrochemical platform for highly sensitive PSA quantification. The electrochemical immunosensor has been designed by immobilizing aptamers on the screen-printed electrode (SPE) surface modified by GA/AuNPs/Nafion. Scanning electron microscopy (SEM), Raman spectra, and electrochemical characterization demonstrated the successful combination of GA/AuNPs/Nafion/SPE. Based on electrochemical impedance spectroscopy (EIS), the proposed immunosensor has demonstrated excellent electrochemical performance, exhibiting sensitive and stable responses for electrochemical detection of PSA ranging from 0.05 to 50 ng∙mL−1 with a limit of detection (LOD) of 0.0306 ng∙mL−1. This study has great potential application in PSA detection and provides a valuable reference for point-of-care testing (POCT) of prostate cancer. [ABSTRACT FROM AUTHOR]

Graphene–WO 3 composites mixed with different amounts of graphene (0, 0.1, 0.5, 1 and 3 wt%) were prepared by hydrothermal method at 180 °C for 24 h. The as-prepared graphite oxide, graphene and graphene–WO 3 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and Raman spectroscopy, respectively. The effect of the amount of graphene in the composites on the gas-sensing responses and the gas-sensing selectivity of the materials was investigated. The experimental results revealed that the sensor based on 0.1 wt% graphene–WO 3 composite exhibited high response and good selectivity to acetaldehyde vapor at 100 °C, the optimum operating temperature of this sensor to 1000 ppm acetaldehyde vapor decreased from 180 °C to 100 °C comparing with that of pure WO 3 . The response time and the recovery time for 100 ppm acetaldehyde vapor were 250 s and 225 s, respectively. [ABSTRACT FROM AUTHOR]