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Abstract Polyproline II (PPII) peptide sequences are recognized as promising biomaterials because of their attractive antifouling properties. However, the mechanisms behind their antifouling behavior have not been fully characterized. In this work we show that PPII peptide coverage, controlled by adsorption time, significantly reduces the fouling of bovine serum albumin (BSA, a model foulant). In addition, guest residues introduced into the PPII sequence are shown to significantly impact BSA adsorption as well as human mesenchymal stem cell (hMSC) spreading. This research will help guide future PPII peptide designs for incorporation into novel biomaterials. Graphical abstract 

Abstract The significance of easily detecting rare earth elements (REEs) has increased due to the growing demand for REEs. Addressing this need, we present an innovative electrochemical biosensor, focusing on cerium as a model REE. This biosensor utilizes a modified EF‐hand loop peptide sequence, incorporating cysteine for covalent attachment to a gold working electrode and tyrosine as an electrochemically active amino acid. The sensor was designed such that binding to cerium induces a conformational change in the peptide, affecting tyrosine's proximity to the electrode surface, modulating the current. A calibration curve was generated from cyclic voltammetry current peaks at ~0.55–0.65 V versus a silver pseudo‐reference electrode, with cerium concentrations ranging from 0 to 67 μM in artificial urine. The sensor exhibited a biologically relevant limit of detection of 35 μM and a sensitivity of −0.0024 ± 0.002 (μA μM)⁻¹. These findings offer insights into designing peptide sequences for electrochemical biosensing. 

Abstract Surface-grafted elastin has found a wide range of uses such as sensing, tissue engineering and capture/release applications because of its ability to undergo stimuli-responsive phase transition. While various methods exist to control surface grafting in general, it is still difficult to control orientation as attachment occurs. This study investigates using an electric field as a new approach to control the surface-grafting of short elastin-like polypeptide (ELP). Characterization of ELP grafting to gold via quartz crystal microbalance with dissipation, atomic force microscopy and temperature ramping experiments revealed that the charge/hydrophobicity of the peptides, rearrangement kinetics and an applied electric field impacted the grafted morphology of ELP. Specifically, an ELP with a negative charge on the opposite end of the surface-binding moiety assembled in a more upright orientation, and a sufficient electric field pushed the charge away from the surface compared to when the same peptide was assembled in no electric field. In addition, this study demonstrated that assembling charged ELP in an applied electric field impacts transition behavior. Overall, this study reveals new strategies for achieving desirable and predictable surface properties of surface-bound ELP.