Biosensors based on the two-dimensional layered nanomaterials transition metal dichalcogenides such as WS2 and MoS2 have shown broad applications, while they largely rely on the utilization of single stranded DNA as probe biomolecules. Herein we have constructed novel WS2- and MoS2- based biosensing platforms using peptides as probe biomolecules. We have revealed for the first time that the WS2 and MoS2 nanosheets display a distinct adsorption for Arg amino acid and particularly, Arg-rich peptdies. We have demonstrated that the WS2 and MoS2 dramatically quench the fluorescence of our constructed Arg-rich probe peptide, while the hybridization of the probe peptide with its target collagen sequence leads to the fluorescence recovery. The WS2-based platform provides a sensitive fluorescence-enhanced assay that is highly specific to the target collagen peptide with little interferences from other proteins. This assay can be applied for quantitative detection of collagen biomarkers in complex biological fluids. The successful development of WS2- and MoS2- based biosensors using non-ssDNA probes opens great opportunities for the construction of novel multifunctional biosensing platforms, which may have great potential in a wide range of biomedical field.

Collagen mimetic scaffolds play a pivotal role in regenerative medicine and tissue engineering due to their extraordinary structural and biological features. We have herein, for the first time, reported the construction of luminescent lanthanide–collagen peptide hybrid three-dimensional nanofibrous scaffolds, which well mimic the characteristic architectural structure of native collagen. Three collagen mimetic peptides, composed of repetitive central (GPO)7 sequences and altered terminal amino acids, have been shown to consistently self-assemble to form biocompatible nanofibers under the trigger of a variety of lanthanide ions, which also functionalize the assembled materials with easily tunable photoluminescence. Furthermore, the collagen peptide–lanthanide hybrid scaffolds possess programmable pH-responsive features. The lanthanide ion-mediated assembly of all three collagen peptides are conveniently and reversibly regulated by pH, while their pH-dependent patterns are finely tuned by the identity of terminal amino acids. Using camptothecin and cefoperazone sodium as two model drugs, the drug-loading and releasing efficiency of the collagen peptide–lanthanide scaffolds are nicely modulated by pH, demonstrating the efficacy of these nanofibrous scaffolds as pH-responsive drug carriers. These novel luminescent collagen peptide–lanthanide scaffolds provide a facile system for pH-controlled drug delivery, suggesting promising applications in the development of therapies for many diseases.

Bolaamphiphile-like collagen mimetic peptides with charged aspartic acids at both terminals may provide a facile peptide-based approach to construct well-defined nanostructures.

Amphiphile-like collagen mimic peptides with terminal aspartic acids may provide a general and convenient strategy to create well-defined nanostructures.

Osteogenesis imperfecta (OI) is a hereditary bone disorder with various phenotypes ranging from mild multiple fractures to perinatal lethal cases, and it mainly results from the substitution of Gly by a bulkier residue in type I collagen. Triple‐helical peptide models of Gly mutations have been widely utilized to decipher the etiology of OI, although these studies are mainly limited to characterizing the peptide features, such as stability and conformation in the solution state. Herein, we have constructed a new series of triple‐helical peptides DD(GPO)5ZPO(GPO)4DD (Z=Ala, Arg, Asp, Cys, Glu, Ser, and Val) mimicking the most common types of observed OI cases. The inclusion of special terminal aspartic acids enables these collagen mimetic peptides to self‐assemble to form nanomaterials upon the trigger of lanthanide ions. We have for the first time systematically evaluated the effect of different OI mutations on the aggregated state of collagen mimetic peptides. We have revealed that the identity of the Gly‐substituting residue plays a determinant role in the morphology and secondary structure of the collagen peptide assemblies, showing that bulkier residues tend to result in a disruptive secondary structure and defective morphology, which lead to more severe OI phenotypes. These findings of osteogenesis imperfecta collagen mimetic peptides in the aggregation state provide novel perspectives on the molecular mechanism of osteogenesis imperfecta, and may aid the development of new therapeutic strategies.