Photocatalytic fuel cells (PFCs) have proven to be effective for generating electricity and degrading pollutants with a goal to resolve environmental and energy problems. However, the degradation of persistent organic pollutants (POPs), such as perfluorooctanoic acid (PFOA), remains challenging. In the present work, a porous coral-like WO3/W (PCW) photoelectrode with a well-designed energy band structure was used for the photoelectrocatalytic degradation of POPs and the simultaneous generation of electricity. The as-constructed bionic porous coral-like nanostructure greatly improved the light-harvesting capacity of the PCW photoelectrode. A maximum photocurrent density (0.31 mA/cm2) under visible light (λ > 420 nm) irradiation and a high incident photon conversion efficiency (IPCE) value (5.72% at 420 nm) were achieved. Because of the unique porous coral-like structure, the suitable energy band position, and the strong oxidation ability, this PCW photoelectrode-based PFC system exhibited a strong ability for simultaneous photoelectrocatalytic degradation of PFOA and electricity generation under visible-light irradiation, with a power output of 0.0013 mV/cm2 using PFOA as the fuel. This work provides a promising way to construct a reliable PFC using highly toxic POPs to generate electricity.

Tumor-derived exosomes are considered as a potential marker in liquid biopsy for malignant tumor screening. The development of a sensitive, specific, rapid, and cost-effective detection strategy for tumor-derived exosomes is still a challenge. Herein, a visualized and easy detection method for exosomes was established based on a molybdenum disulfide nanoflower decorated iron organic framework (MoS2-MIL-101(Fe)) hybrid nanozyme-based CD63 aptamer sensor. The CD63 aptamer, which can specifically recognize and capture tumor-derived exosomes, enhanced the peroxidase activity of the hybrid nanozyme and helped to catalyze the 3,3′,5,5′-tetramethylbenzidine (TMB)-H2O2 system to generate a stronger colorimetric signal, with its surface modification on the hybrid nanozyme. With the existence of exosomes, CD63 aptamer recognized and adsorbed them on the surface of the nanozyme, which rescued the enhanced peroxidase activity of the aptamer-modified nanozyme, resulting in a deep-to-moderate color change in the TMB-H2O2 system where the change is visible and can be monitored with ultraviolet-visible spectroscopy. In the context of optimal circumstances, the linear range of this exosome detection method is measured to be 1.6 × 104 to 1.6 × 106 particles/μL with a limit of detection as 3.37 × 103 particles/μL. Generally, a simple and accessible approach to exosome detection is constructed, and a nanozyme-based colorimetric aptamer sensor is proposed, which sheds light on novel oncological biomarker measurements in the field of biosensors.