In Situ Assembly of Nanomaterials and Molecules for the Signal Enhancement of Electrochemical Biosensors

Aggregation-induced signal amplification strategy based on peptide self-assembly for ultrasensitive electrochemical detection of melanoma biomarker

The detection of melanoma circulating biomarker in liquid biopsies is current under evaluation for being potentially utilized for earlier cancer diagnosis and its metastasis. Herein, we developed a non-invasive electrochemical approach for ultrasensitive detection of the S100B, serving as a potential promising blood circulating biomarker of melanoma, based on an aggregation-induced signal amplification (AISA) strategy via in-situ peptide self-assembly. The fundamental principle of this assay is that the designed amphiphilic peptides (C16-Pep-Fc), fulfilling multiple functions, feature both a recognition region for specific binding to S100B and an aggregation (self-assembly) region for the formation of peptide nanomicelles under mild conditions. The C16 tails were encapsulated within the hydrophobic core of the aggregates, while the relatively hydrophilic recognition fragment Pep and Fc tag were exposed on the outer surface for subsequent recognition of S100B and signal output. AISA provided remarkable accumulation of electroactive Fc moieties that enabled ultrasensitive S100B detection of as low as 0.02 nM, which was 10-fold lower than un-amplified approach and better than previously reported assays. As a proof-of-concept study, further experiments also highlighted the good reproducibility and stability of AISA and demonstrated its usability when applied to simulated serum samples. Hence, this work not only presented a valuable assay tool for ultrasensitive detecting protein biomarker, but also advocated for the utilization of aggregation-induced signal amplification in electrochemical biosensing system, given its considerable potential for future practical applications.

DNA Origami-Based Letterpress Printing of Gold Nanostructures with Predesigned Morphologies

Creating customizable metallic nanostructures in a simple and controllable manner has been a long-standing goal in nanoscience. In this study, we use DNA origami as a letterpress printing plate and gold nanoparticles as ink to produce predesigned gold nanostructures. The letterpress plate is reusable, enabling the repetitive production of predesigned gold nanostructures. Furthermore, by modifying the DNA origami letterpress plate on magnetic beads, we can simplify the printing processes. We have successfully printed gold nanoparticle dimers, trimers, straight and quadrilateral tetramers, and other nanostructures. Our approach improves the flexibility and stability of metallic nanostructures, simplifying both their design and their operation. It promises universal applicability in the fabrication of metamaterials, biosensors, and surface plasma nanooptics.

Recent advances in the peptide-based biosensor designs

Biosensors have rapidly emerged as a high-sensitivity and convenient detection method. Among various types of biosensors, optical and electrochemical are the most commonly used. Conventionally, antibodies have been employed to ensure specific interaction between the transmission material and analytes. However, there has been increasing recognition of peptides as a promising recognition element for biosensor development in recent years. The use of peptides as recognition elements provides high level of specificity, sensitivity, and stability for the detection process. The combination of peptide designs and optical or electrochemical detection methods has significantly improved biosensor efficacy. These advancements present opportunities for developing biosensors with diverse functions that can be used to lay a strong scientific foundation for the development of personalized medicine and various other fields. This paper reviews the recent advancements in the development and application of peptide-based optical and electrochemical biosensors, as well as their prospects as a sensor type.

Editorial for Special Issue: "Preparation of Nanomaterial Modified Electrode and Its Sensing Application"

Electrochemical sensors have attracted enormous attention for their precision, high sensitivity, rapid response, and ease-of-use for analysis [...].