In recent years, along with the rapid development of relevant biological fields, there has been a tremendous motivation to combine molecular imprinting technology (MIT) with biosensing. In this situation, bioprobes and biosensors based on molecularly imprinted polymers (MIPs) have emerged as a reliable candidate for a comprehensive range of applications, from biomolecule detection to drug tracking. Unlike their precursors such as classic immunosensors based on antibody binding and natural receptor elements, MIPs create complementary cavities with stronger binding affinity, while their intrinsic artificial polymers facilitate their use in harsh environments. The major objective of this work is to review recent MIP bioprobes and biosensors, especially those used for biomolecules and drugs. In this review, MIP bioprobes and biosensors are categorized by sensing method, including optical sensing, electrochemical sensing, gravimetric sensing and magnetic sensing, respectively. The working mechanism(s) of each sensing method are thoroughly discussed. Moreover, this work aims to present the cutting-edge structures and modifiers offering higher properties and performances, and clearly point out recent efforts dedicated to introduce multi-sensing and multi-functional MIP bioprobes and biosensors applicable to interdisciplinary fields.

Amyloid peptide (AP) self-assembly is a hierarchical process. However, the mechanistic rule of guiding peptides to organize well-ordered nanostructure in a clear and precise manner remains poorly understood. Herein we explored the molecular insight of AP motif aggregates underlying hierarchical process with helical fibrillar structure by atomic force microscope, cryo-electron microscopy (cryo-EM), and molecular dynamics simulation. AP assembly encompasses well-ordered twisted fibrils with uniform morphology, size, and periodicity. More importantly, a heterozipper β-sheet was identified in a protofilament of AP assembly determined by cryo-EM with a high resolution of 3.5 Å. Each peptide heterozipper was further composed of two antiparallel β strands and arranged by an alternative manner in a protofilament. The hydrophobic core and hydrophilic area in each zipper played the significant role for peptide assembling. This work proposed and verified the rule facilitating the basic building unit to form twisted fibrils and gave the explanation of peptide hierarchical assembling.

Regulating the mechanical performance of a material, especially for protein hydrogels, in situ from elasticity to plasticity and vice versa would be difficult but highly anticipated due to the diversity of promising applications. Herein, we proposed a strategy to prepare versatile hydrogels with tunable mechanical properties. It was demonstrated that we could rapidly prepare regenerated silk fibroin/gelatin (RSF/Gel) copolymer hydrogels by chemically modifying RSF by glycidyl methacrylate (RSF-MA) and gelatin by methacrylic anhydride (Gel-MA) under UV light in 60 s. Furthermore, the RSF/Gel hydrogels showed tunable mechanical properties by controlling the β-sheet content of SF, which can realize reversible switch between elasticity and plasticity in situ. The significant alteration of tensile stress at break and tensile elastic modulus at 10% strain was achieved with 720 times and 2000 times improvement from an elastic to plastic hydrogel. The compressive elastic modulus at 50% strain of a plastic hydrogel was improved to 3.6 MPa, which was 62 times higher than that of an elastic hydrogel. In addition, the performance of drug release of RSF/Gel hydrogel microneedles could be modulated by controlling the β-sheet content of SF, which could be a drug carrier and also be other promising biomaterials for a variety of biological and clinical applications.

Fast monitoring oral bacterial infection, bacterial clearance and repairing of enamel damage caused by dental caries relied on a system to repair in-situ in an effective way, is the major...

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