Bioconjugation of peroxidase-like nanostructures with natural enzyme for in-situ amplified conductometric immunoassay of tissue polypeptide antigen in biological fluids

Cubic Na0.5Bi0.5TiO3 nanoperovskite significantly expands the application of sensitive immunosensor for the detection of carcinoembryonic antigen

Nanosized sodium bismuth perovskite titanate (NBT) was synthesized and first used as the electrochemical immune sensing platform for the sensitive detection of carcinoembryonic antigen (CEA). Gold nanoparticles (Au NPs) grew on the surface of NBT through forming Au-N bond to obtain Au@NBT, and a label-free electrochemical immunosensor was proposed using Au@NBT as an immunosensing recognizer towards CEA. The well-ordered crystal structure of NBT was not changed at all after the modification of Au NPs outside, but significantly improved the conductivity, catalytic activity, and biocompatibility of the Au@NBT-modified electrode. The unique cubic crystal nanostructure of NBT offered a large active area for both Au NP modification and the subsequent immobilization of biomolecules over the electrode surface, triggering the effective generation of promising properties of the proposed Au@NBT-based electrochemical immunosensor. As expected, favorable detection performances were achieved using this immunosensor towards CEA detection, where a good linear relationship between the current response and CEA concentration was obtained in the concentration range 10 fg mL-1 to 100 ng mL-1 with a low detection limit (LOD) of 13.17 fg mL-1. Also, the significantly enhanced selectivity, and stability guaranteed the promising electrochemical properties of this immunosensor. Furthermore, the analysis of real serum samples verified the high feasibility of this new method in clinical CEA detection. This work opens a new window for the application of nanoperovskite in the early detection of CEA.

Nanomaterials for Electrochemical Immunosensing

Electrochemical immunosensors resulting from a combination of the traditional immunoassay approach with modern biosensors and electrochemical analysis constitute a current research hotspot. They exhibit both the high selectivity characteristics of immunoassays and the high sensitivity of electrochemical analysis, along with other merits such as small volume, convenience, low cost, simple preparation, and real-time on-line detection, and have been widely used in the fields of environmental monitoring, medical clinical trials and food analysis. Notably, the rapid development of nanotechnology and the wide application of nanomaterials have provided new opportunities for the development of high-performance electrochemical immunosensors. Various nanomaterials with different properties can effectively solve issues such as the immobilization of biological recognition molecules, enrichment and concentration of trace analytes, and signal detection and amplification to further enhance the stability and sensitivity of the electrochemical immunoassay procedure. This review introduces the working principles and development of electrochemical immunosensors based on different signals, along with new achievements and progress related to electrochemical immunosensors in various fields. The importance of various types of nanomaterials for improving the performance of electrochemical immunosensor is also reviewed to provide a theoretical basis and guidance for the further development and application of nanomaterials in electrochemical immunosensors.

Stabilized enzyme immobilization on micron-size PSt–GMA microspheres: different methods to improve the carriers' surface biocompatibility

Stabilized immobilization of biomacromolecules on carriers with appropriate orientation and minimum conformational changes is very important in the biochemical and biomedical fields.

Electrochemical immunosensors and their recent nanomaterial-based signal amplification strategies: a review

In recent years, tremendous advances have been made in biosensors based on nanoscale electrochemical immunosensors for use in the fields of agriculture, food safety, biomedicine, quality control, and environmental and industrial monitoring.