A Miniaturized Impedimetric Immunosensor for the Competitive Detection of Adrenocorticotropic Hormone.
Nan LiEgor M LarinKagan KermanPublished in: Sensors (Basel, Switzerland) (2017)
Adrenocorticotropic hormone (ACTH) plays an essential role in regulating corticosteroid hormone production, which has important functions in a myriad of critical physiological functions. In this proof-of-concept study, a miniaturized immunosensor was developed for the highly sensitive detection of ACTH using electrochemical impedance spectroscopy (EIS) in connection with disposable screen-printed gold electrodes (SPGEs). A film of 3,3'-dithiobis[sulfosuccinimidylpropionate] (DTSSP) was prepared to immobilize anti-ACTH antibodies covalently on the nanostructured SPGE surface. The surface-immobilized anti-ACTH antibodies captured the biotinylated ACTH (biotin-ACTH) and non-labelled ACTH for the competitive immunoassay. After coupling of a streptavidin-alkaline phosphatase conjugate (Streptavidin-ALP), the bio-catalysed precipitation of an insoluble and insulating product onto the sensing interface changed the charge transfer resistance (Rct) characteristics significantly. The detection limit of 100 fg/mL was determined for ACTH in a 5 μL sample volume, which indicated that this versatile platform can be easily adapted for miniaturized electrochemical immunosensing of cancer marker biomolecules. High selectivity and sensitivity of our immunoassay to detect ACTH in real samples demonstrated its promising potential for future development and applications using clinical samples.
Keyphrases
- sensitive detection
- label free
- loop mediated isothermal amplification
- quantum dots
- gold nanoparticles
- high throughput
- computed tomography
- room temperature
- mass spectrometry
- climate change
- real time pcr
- squamous cell carcinoma
- magnetic resonance
- drug delivery
- human health
- squamous cell
- current status
- single cell
- low cost
- liquid chromatography
- simultaneous determination
- magnetic nanoparticles