In vitro selection of tacrolimus binding aptamer by systematic evolution of ligands by exponential enrichment method for the development of a fluorescent aptasensor for sensitive detection of tacrolimus

J Pharm Biomed Anal. 2020 Jan 5:177:112853. doi: 10.1016/j.jpba.2019.112853. Epub 2019 Aug 31.

Abstract

Tacrolimus (TAC) is an immunosuppressant for preventing solid-organ transplant rejection. Because of its narrow therapeutic window, analytical methods which can detect TAC in serum samples with high accuracy and reliability are required. In this study, specific aptamers (Apt122 and Apt125) for TAC were isolated via systematic evolution of ligands by exponential enrichment method using magnetic beads to immobilize the target. After determination of binding constants of aptamers by flow cytometry analysis, Apt122 was selected and labeled with ATTO 647 N as a fluorophore to develop a fluorescent sensing platform for detection of TAC using graphene oxide (GO) as a fluorescence quencher. The designed aptasensor could detect TAC in phosphate buffer saline (10 mM PBS) and serum samples with detection limits as low as 1.4 and 2.5 nM, respectively.

Keywords: Aptamer; Fluorescent sensing method; SELEX; Serum; Tacrolimus.

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods
  • Drug Monitoring / instrumentation
  • Drug Monitoring / methods*
  • Feasibility Studies
  • Fluorescent Dyes / chemistry
  • Graphite / chemistry
  • Humans
  • Immunosuppressive Agents / administration & dosage
  • Immunosuppressive Agents / blood*
  • Immunosuppressive Agents / chemistry
  • Ligands
  • Limit of Detection
  • Reproducibility of Results
  • SELEX Aptamer Technique / methods*
  • Tacrolimus / administration & dosage
  • Tacrolimus / blood*
  • Tacrolimus / chemistry

Substances

  • Aptamers, Nucleotide
  • Fluorescent Dyes
  • Immunosuppressive Agents
  • Ligands
  • graphene oxide
  • Graphite
  • Tacrolimus