Sensitive and high-throughput protein analysis based on CdS@g-C3N4 heterojunction-modified spatial-resolved rotatable electrode array

Synthesis, Functionalization, and Biomedical Applications of Iron Oxide Nanoparticles (IONPs)

Iron oxide nanoparticles (IONPs) have garnered significant attention in biomedical applications due to their unique magnetic properties, biocompatibility, and versatility. This review comprehensively examines the synthesis methods, surface functionalization techniques, and diverse biomedical applications of IONPs. Various chemical and physical synthesis techniques, including coprecipitation, sol-gel processes, thermal decomposition, hydrothermal synthesis, and sonochemical routes, are discussed in detail, highlighting their advantages and limitations. Surface functionalization strategies, such as ligand exchange, encapsulation, and silanization, are explored to enhance the biocompatibility and functionality of IONPs. Special emphasis is placed on the role of IONPs in biosensing technologies, where their magnetic and optical properties enable significant advancements, including in surface-enhanced Raman scattering (SERS)-based biosensors, fluorescence biosensors, and field-effect transistor (FET) biosensors. The review explores how IONPs enhance sensitivity and selectivity in detecting biomolecules, demonstrating their potential for point-of-care diagnostics. Additionally, biomedical applications such as magnetic resonance imaging (MRI), targeted drug delivery, tissue engineering, and stem cell tracking are discussed. The challenges and future perspectives in the clinical translation of IONPs are also addressed, emphasizing the need for further research to optimize their properties and ensure safety and efficacy in medical applications. This review aims to provide a comprehensive understanding of the current state and future potential of IONPs in both biosensing and broader biomedical fields.

P-doped porous carbon derived from walnut shell for zinc ion hybrid capacitors

Zinc ion hybrid capacitors (ZHCs) are expected to be candidates for large-scale energy storage products due to their high power density and large energy density. Due to their low cost and stability, carbon materials are generally the first choice for the cathode of ZHCs, but they face a challenge in the serious self-discharge behavior. Herein, zinc ion hybrid capacitors with high-performance are successfully assembled using a porous carbon cathode derived from low-cost p-doped waste biomass and a commercial zinc foil anode. The p-doped walnut shell ZHCs delivered a specific capacity of 158.9 mA h g-1 with an energy density of 127.1 W h kg-1 at a low current density. More importantly, the device had outstanding anti-self-discharge characteristics (retaining 77.98% of its specific capacity after a 72 h natural self-discharge test) and long-term cycle stability (retaining 88.2% of its initial specific capacity after 15 000 cycles at 7.5 A g-1). This work presents guidance and support for the design and optimization of electrode materials for zinc ion supercapacitors and next-generation aqueous zinc ion energy storage performance.

Microfluidic Ratiometric Photoelectrochemical Biosensor Using a Magnetic Field on a Photochromic Composite Platform: A Proof-of-Concept Study for Magnetic-Photoelectrochemical Bioanalysis

Integrating a microfluidic sensor with a ratiometric photoelectrochemical (PEC) strategy to build a bioanalysis device for actual sample testing is often limited to large-volume space-resolution equipment and wavelength-dependent or potential-dependent paired photoactive materials. This work reports a microfluidic ratiometric magnetic-photoelectrochemical (M-PEC) biosensor on the photochromic composite platform to solve the above problems. In particular, as a proof-of-concept study, the platform Bi₂WO_6-x/amorphous BiOCl nanosheets/Bi₂S₃ (p-BWO-s) mediated by photochromic color centers and the magnetic photoactive secondary antibody marker ZnFe₂O₄@Ag₂O are integrated on the microfluidic biosensor. By enhancement of the photochromic color centers, p-BWO-s outputs a considerable photocurrent signal. Meanwhile, the photoactivity of the secondary antibody marker can be changed with a magnetic field; thus, different photocurrent signals can be obtained to realize ratiometric detection. The quenching photocurrent signal without the magnetic field and the difference photocurrent signal under the magnetic field are quantitatively related to the target concentration, which unfolds a novel general strategy for bioanalysis. Different from traditional ratiometric PEC biosensors, this work characterizes the first ratiometric PEC biosensor based on an external magnetic field. Generally speaking, combined with different biorecognition cases, this scheme with good expansibility brings a unique new perspective.