The Influence of Graphene on the Electrical Communication Through Organic Layers on Graphite and Gold Electrodes

Graphene Biodevices for Early Disease Diagnosis Based on Biomarker Detection

The early diagnosis of diseases plays a vital role in healthcare and the extension of human life. Graphene-based biosensors have boosted the early diagnosis of diseases by detecting and monitoring related biomarkers, providing a better understanding of various physiological and pathological processes. They have generated tremendous interest, made significant advances, and offered promising application prospects. In this paper, we discuss the background of graphene and biosensors, including the properties and functionalization of graphene and biosensors. Second, the significant technologies adopted by biosensors are discussed, such as field-effect transistors and electrochemical and optical methods. Subsequently, we highlight biosensors for detecting various biomarkers, including ions, small molecules, macromolecules, viruses, bacteria, and living human cells. Finally, the opportunities and challenges of graphene-based biosensors and related broad research interests are discussed.

Controlled Silanization: High Molecular Regularity of Functional Thiol Groups on Siloxane Coatings

A comparative study on deposition and molecular regularity of two organosilanes, i.e., commercially available (3-mercaptopropyl)trimethoxysilane (MPTMS) and newly developed mercaptopropylsilatrane (MPS), was conducted in this work. MPTMS and MPS were applied to modify silicon surfaces to characterize their deposition kinetics, surface morphology, thickness, and elemental composition and the reactivity of thiol end groups based on gold-thiol and thiol-ene chemistries. MPS possesses a tricyclic caged structure and a transannular N → Si dative bond, making it chemically stable and controllable to avoid fast hydrolysis and aggregation in solution. The results indicate that MPS allows faster deposition and better formation of thin and homogeneous films than MPTMS. More importantly, the functional thiol groups on MPS coatings enable immobilization of a large amount of gold nanoparticles and effective thiol-ene photopolymerization with zwitterionic sulfobetaine acrylamide. Postmodification on silanized surfaces with MPS endows excellent plasmonic and antifouling properties, potentially leading to valuable applications to biosensing and biomaterials. The work demonstrated the feasibility and applicability of the functional silatrane molecule for surface silanization in a controlled manner.