Urology/Head & Neck
Ashkan Zandi, PhD
Research Faculty
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA, United States
Fatemeh Shojaeian, MD, MPH
Postdoctoral Research Fellow
Johns Hopkins University School of Medicine, United States
Fatemeh Shojaeian, MD, MPH
Postdoctoral Research Fellow
Johns Hopkins University School of Medicine, United States
Mark El-Deiry, MD
Associate Professor
Department of Otolaryngology-Head and Neck Surgery, Winship Cancer Institute of Emory University, Atlanta, Georgia, USA, United States
Cletus A. Arciero, M.D.
Professor, Division of Surgical Oncology, Department of Surgery
Emory University School of Medicine
Atlanta, Georgia, United States
Ali Adibi, PhD
Professor
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA, United States
Introduction: Mucormycosis (Zygomycosis) is a severe fungal infection with life-threatening implications for immunocompromised patients, including those undergoing cancer treatment. Timely and precise identification is crucial for effective clinical management. This study presents a biosensor for rapid, highly sensitive mucormycosis detection, spanning from initial in-vitro experiments to ex-vivo applications using human nasal tissue. The biosensor selectively detects two key mucormycosis components: mannans (essential cell wall constituents) and melanin (a unique pigment).
Methods:
Method: A graphene-based biosensor was developed to measure mannans and melanin, utilizing biotin-streptavidin immobilization and specific binders. This biosensor employed both differential pulse voltammograms (DPV) and open circuit potential–electrochemical impedance spectroscopy (OCP-EIS) for analysis. Mucormycosis was cultured by transferring its fragments onto sabouraud dextrose agar (SDA) plates, with incubation in the temperature range of 30°C to 37°C. To evaluate the biosensor's performance, tests were conducted using in-vitro and ex-vivo samples. The in-vitro phase involved cultured fungal spores in buffer medium, quantified using a hemocytometer, including 25 different cultures containing 1 million to 100 spores per milliliter, each tested three times. Negative controls with no spores or fungi were also included. In the ex-vivo phase, 18 post dissection human nasal tissue samples were analyzed using the biosensor, with pathological evaluation serving as the reference. DPV involved a potential range from -0.2 to 0.6 V, and EIS included a frequency range from 0.1 Hz to 1 MHz. 200 µl of the redox couple [Fe(CN)6]3−–[Fe(CN)6]4− was added to each 800 µl of the samples to monitor electrode surface modifications.
Results:
Results: The biosensor reliably detected mucormycosis samples with fewer than 100 spores in 1 ml of buffer solution. The biosensor showed 84% and 76% sensitivity and specificity, respectively (Area Under the Curve (AUC): 0.785, P < 0.01). In the human nasal samples, the biosensor also exhibited reliable performance in resected human samples, with sensitivity and specificity of 78 and 72% (AUC: 0.762, P < 0.01).
Conclusions:
Conclusion: This graphene-based biosensor employs electrochemical methods to detect mucormycosis with notable sensitivity and specificity. To our knowledge, it represents the first-of-its-kind mucormycosis biosensor, poised to empower diagnosis by enabling early intervention and effective treatment.