Latest news and results from our research
- Monitoring amyloid-β 42 conformational change using a spray-printed graphene electrode. Paper available here.
Up to now, the reproducibility and stability of graphene-based electrochemical sensors have represented an obstacle to the development of practical biosensing techniques. In this paper we report a cost-effective and highly reproducible graphene-based electrochemical sensing platform to monitor the kinetic conformational change of amyloidogenic proteins. The sensor surface is spray-printed with a graphene oxide layer and then electrochemically reduced to achieve excellent sensitivity to the redox current. The reproducibility of these sensors in terms of redox peak position, intensity and electroactive area has been proved to be high. These sensors are used to monitor the conformational changes of amyloid-β 42 via the change in the oxidation current of tyrosine, which is caused by different electrochemical accessibility during the aggregation process. The aggregation process detected at these graphene electrochemical sensors shows a good correlation with the fluorescence assay. The proposed platform provides a complementary technique to aid understanding of the detailed process of amyloidogenic protein aggregation and the mechanism of neurodegenerative diseases as well as helping to promote the development of disease-prevention strategies.
- New paper accepted for publication, 12/02/2021: Carbon-Dot-Enhanced Graphene Field-Effect Transistors for Ultrasensitive Detection of Exosomes
Graphene field-effect transistors (GFETs) are suitable building blocks for high-performance electrical biosensors, because graphene inherently exhibits a strong response to charged biomolecules on its surface. However, achieving ultralow limit-of-detection (LoD) is limited by sensor response time and screening effect. Herein, we demonstrate that the detection limit of GFET biosensors can be improved significantly by decorating the uncovered graphene sensor area with carbon dots (CDs). The developed CDs-GFET biosensors used for exosome detection exhibited higher sensitivity, faster response, and three orders of magnitude improvements in the LoD compared with nondecorated GFET biosensors. A LoD down to 100 particles/μL was achieved with CDs-GFET sensor for exosome detection with the capability for further improvements. The results were further supported by atomic force microscopy (AFM) and fluorescent microscopy measurements. The high-performance CDs-GFET biosensors will aid the development of an ultrahigh sensitivity biosensing platform based on graphene for rapid and early diagnosis of diseases.
- Professor Norbert Klein introduces graphene-based COVID-19 detection to ISST Innvoation Ecosystem
Read the article based off Norbert's talk here.
Facile biosensors for rapid detection of COVID-19
Currently the world is being challenged by a public health emergency caused by the coronavirus pandemic (COVID-19). Extensive efforts in testing for coronavirus infection, combined with isolating infected cases and quarantining those in contact, have proven successful in bringing the epidemic under control. Rapid and facile screening of this disease is in high demand. This review summarises recent advances in strategies reported by international researchers and engineers concerning how to tackle COVID-19 via rapid testing, mainly through nucleic acid- and antibody- testing. The roles of biosensors as powerful analytical tools are emphasized for the detection of viral RNAs, surface antigens, whole viral particles, antibodies and other potential biomarkers in human specimen. We critically review in depth newly developed biosensing methods especially for in-field and point-of-care detection of SARS-CoV-2. Additionally, this review describes possible future strategies for virus rapid detection. It helps researchers working on novel sensor technologies to tailor their technologies in a way to address the challenge for effective detection of COVID-19.