A lable-free SPR biosensor based on one peptide sequence with three recognition sites for O-GlcNAc transferase detection

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.

Perspectives and trends in advanced optical and electrochemical biosensors based on engineered peptides

With the advancement of life medicine, in vitro diagnostics (IVD) technology has become an auxiliary tool for early diagnosis of diseases. However, biosensors for IVD now face some disadvantages such as poor targeting, significant antifouling properties, low density of recognized molecules, and poor stability. In recent years, peptides have been demonstrated to have various functions in unnatural biological systems, such as targeting properties, antifouling properties, and self-assembly properties, which indicates that peptides can be engineered. These properties of peptides, combined with their good biocompatibility, can be well applied to the design of biosensors to solve the problems mentioned above. This review provides an overview of the properties of engineered functional peptides and their applications in enhancing biosensor performance, mainly in the field of optics and electrochemistry.

Application of functional peptides in the electrochemical and optical biosensing of cancer biomarkers

Early screening and diagnosis are the most effective ways to prevent the occurrence and progression of cancers, thus many biosensing strategies have been developed to achieve economic, rapid, and effective detection of various cancer biomarkers. Recently, functional peptides have been gaining increasing attention in cancer-related biosensing due to their advantageous features of a simple structure, ease of synthesis and modification, high stability, and good biorecognition, self-assembly and antifouling capabilities. Functional peptides can not only act as recognition ligands or enzyme substrates for the selective identification of different cancer biomarkers but also function as interfacial materials or self-assembly units to improve the biosensing performances. In this review, we summarize the recent advances in functional peptide-based biosensing of cancer biomarkers according to the used techniques and the roles of peptides. Particular attention is focused on the use of electrochemical and optical techniques, both of which are the most commonly used techniques in the field of biosensing. The challenges and promising prospects of functional peptide-based biosensors in clinical diagnosis are also discussed.

Ultrasensitive assay of O-GlcNAc transferase using capillary electrophoresis-laser induced fluorescence

O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) is directly associated with the level of O-GlcNAc glycosylation of biomolecules and various diseases, and it is expected to be a promising potential new therapeutic target. Here, we develop a robust and sensitive method for OGT assay based on capillary electrophoresis-laser induced fluorescence (CE-LIF) method. AF-488-modified peptide containing serine active group is designed as substrate for OGT-catalyzed reaction, and nonradioactive UDP-GlcNAc is employed as sugar donor to perform O-GlcNAc glycosylation modification. The enzyme activity of OGT is measured by quantitative determination of glycosylated peptide produced by the reaction. Large volume sample stacking technique for sample injection and a unique fluorescence collection system for LIF detection are adopted to greatly enhance the detection sensitivity, thus a low limit of detection down to 0.23 pM for OGT detection is achieved. The method is successfully applied to detect OGT activity in clinical blood samples with satisfactory accuracy. Our study provides a simple, accurate, and sensitive method with great potential application in clinical diagnosis of O-GlcNAc-related diseases.

Peptide-Derived Biosensors and Their Applications in Tumor Immunology-Related Detection

Small-molecular targeting peptides possess features of biocompatibility, affinity, and specificity, which is widely applied in molecular recognition and detection. Moreover, peptides can be developed into highly ordered supramolecular assemblies with boosting binding affinities, diverse functions, and enhanced stabilities suitable for biosensors construction. In this Review, we summarize recent progress of peptide-based biosensors for precise detection, especially on tumor-related analysis, as well as further provide a brief overview of the progress in tumor immune-related detection. Also, we are looking forward to the prospective future of peptide-based biosensors.