Oligonucleotide-capped nanoporous anodic alumina biosensor as diagnostic tool for rapid and accurate detection of Candida auris in clinical samples

Emerg Microbes Infect. 2021 Dec;10(1):407-415. doi: 10.1080/22221751.2020.1870411.

Abstract

Candida auris has arisen as an important multidrug-resistant fungus because of several nosocomial outbreaks and elevated rates of mortality. Accurate and rapid diagnosis of C. auris is highly desired; nevertheless, current methods often present severe limitations and produce misidentification. Herein a sensitive, selective, and time-competitive biosensor based on oligonucleotide-gated nanomaterials for effective detection of C. auris is presented. In the proposed design, a nanoporous anodic alumina scaffold is filled with the fluorescent indicator rhodamine B and the pores blocked with different oligonucleotides capable of specifically recognize C. auris genomic DNA. Gate opening modulation and cargo delivery is controlled by successful DNA recognition. C. auris is detected at a concentration as low as 6 CFU/mL allowing obtaining a diagnostic result in clinical samples in one hour with no prior DNA extraction or amplification steps.

Keywords: Candida auris; Nanoporous anodic alumina; biosensor; molecular gates; oligonucleotide; rapid diagnosis.

MeSH terms

  • Aluminum Oxide
  • Biosensing Techniques / methods*
  • Candida / genetics
  • Candida / isolation & purification*
  • Candidiasis / diagnosis*
  • Early Diagnosis
  • Humans
  • Molecular Diagnostic Techniques
  • Nanopores
  • Oligonucleotides / chemistry
  • Oligonucleotides / genetics*
  • Rhodamines / chemistry
  • Sensitivity and Specificity
  • Time Factors

Substances

  • Oligonucleotides
  • Rhodamines
  • rhodamine B
  • Aluminum Oxide

Grants and funding

The authors want to thank the Spanish Government (project RTI2018-100910-B-C41 (MCIU/AEI/FEDER, UE)), the Generalitat Valenciana (project PROMETEO/2018/024), Universitat Politècnica de València−Instituto de Investigación Sanitaria La Fe (AURISGATE project) and Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (NANOPATH AND CANDI-EYE projects) for support. L.P thanks MINECO for his predoctoral fellowship. S.S. thanks the Instituto de Salud Carlos III and the European Social Fund for the financial support “Sara Borrell” (CD16/000237).