Covalent linking peptide to hydrothermally reduced graphene oxide for ultrasensitive detection of matrix metalloproteinase 9

Recent advances of graphene-biomacromolecule nanocomposites in medical applications

In recent years, graphene-based composites have received increasing attention due to their high biocompatibility, large specific surface area, high electrical conductivity and unique mechanical properties. The combination of biomacromolecules and graphene provides a promising route for the preparation of novel graphene-based nanocomposites. Novel graphene-based nanocomposites with unique functions could be applied to medicine, biology, biosensors, environmental science, energy storage and other fields. Graphene-biomacromolecule nanocomposites have excellent biocompatibility, outstanding biofunctionality and low cytotoxicity, and have more advantages and development prospects than other traditional graphene-based materials in biological and biomedical fields. In this work, we summarize the research on the covalent and non-covalent interactions between different biomacromolecules (peptides, DNA/RNA, proteins and enzymes) and graphene, as well as the synthesis methods of novel functionalized graphene-biomacromolecule composites in recent years. We mainly introduce the recent advances (last 5 years) of graphene-biomacromolecule nanocomposites in medical applications, such as medical detection and disease treatment. We hope that this review will help readers to understand the methods and mechanisms of biomolecules modifying the surface of graphene, as well as the synthesis and application of graphene-based nanocomposites, which will promote the future developments of graphene-biomolecule composites in biomedicine, tissue engineering, materials engineering, and so on.

Recent advances in the synthesis and applications of graphene-polypeptide nanocomposites

The combination of peptides and graphene-derived materials provides a new way to prepare graphene-based nanocomposites with unique structures, properties, and functions. The modification of graphene with different polypeptides not only improves the biocompatibility and biological recognition ability of graphene-based materials, but also greatly expands their application fields. In this work, we summarize different interactions between graphene and polypeptides, and the synthesis methods of novel functional graphene-polypeptide nanocomposites based on the interactions in recent years (from 2016 to present). In addition, the potential applications of graphene-peptide hybrid nanocomposites in biomedicine, tissue engineering, biosensors, environmental science engineering, optoelectronic materials, and energy storage are introduced. We hope that this review will help readers to understand the methods and mechanisms of the modification of graphene surfaces with biomolecules, and promote readers to understand the synthesis and applications of graphene-based nanocomposites. This work may provide hints and references for the development of peptide sequence design, and biomedical and functional materials, and will help in designing and synthesizing novel graphene-based nanomaterials with unique properties and suitable for various applications in the future.

Clinical Application for Screening Down's Syndrome by Using Carboxylated Graphene Oxide-Based Surface Plasmon Resonance Aptasensors

BACKGROUND

Advanced medical detection technology requires high sensitivity and accuracy to increase the disease detection rate. We showed that carboxyl-functionalized graphene oxide (carboxyl-GO) biosensing materials are capable of accurate detection.

METHODS

We developed a carboxylated GO-based surface plasmon resonance (SPR) aptasensor suitable for screening Down's syndrome in clinical serum. This biosensing material could rapidly and accurately detect hCG protein with a low concentration to identify fetal Down's syndrome. The developed carboxyl-GO-based SPR aptasensor showed excellent sensitivity and limit of detection without the use of antibodies and without any specific preference.

RESULTS

hCG protein detection limits of 1 pM in buffer samples and 1.9 pM in clinical serum samples were achieved. The results showed that the carboxyl-GO-based chip could detect hCG well below the normal physiological level of serum protein (5.0 mIU/mL). High affinity, sensitivity, and better detection limit were obtained in the range of 1.9 pM to 135 pM. The results showed a 5k-fold dilution factor, and that an SPR angle shift of more than 20 millidegrees (mo) was associated with a significant risk of fetal Down's syndrome compared to normal pregnant women. The results clearly showed that the detection of hCG protein in serum samples from pregnant women at 12-19 weeks could be used to screen Down's syndrome with high selectivity and sensitivity.

CONCLUSION

Our findings suggest the potential application of carboxyl-GO film in proof-of-concept studies for serum assays as a new type of SPR material. In addition, peptide and carboxyl-GO films may be conducive to the development of future point of care testing and rapid diagnostic devices for other diseases such as cancer.