DNA-Based Sensor for the Detection of an Organophosphorus Pesticide: Profenofos.
Giulia SelvoliniIoana BăjanOana Hosu-StancioiuCecilia CristeaRobert SăndulescuGiovanna MarrazzaPublished in: Sensors (Basel, Switzerland) (2018)
In this work, we propose an electrochemical DNA aptasensor for the detection of profenofos, an organophosphorus pesticide, based on a competitive format and disposable graphite screen-printed electrodes (GSPEs). A thiol-tethered DNA capture probe, which results to be complementary to the chosen aptamer sequence, was immobilised on gold nanoparticles/polyaniline composite film-modified electrodes (AuNPs/PANI/GSPE). Different profenofos solutions containing a fixed amount of the biotinylated DNA aptamer were dropped onto the realized aptasensors. The hybridisation reaction was measured using a streptavidin-alkaline phosphatase enzyme conjugate, which catalyses the hydrolysis of 1-naphthyl -phosphate. The 1-naphtol enzymatic product was detected by means of differential pulse voltammetry (DPV). The aptasensor showed itself to work as a signal off sensor, according to the competitive format used. A dose response curve was obtained between 0.10 μM and 10 μM with a detection limit of 0.27 μM.
Keyphrases
- label free
- gold nanoparticles
- reduced graphene oxide
- circulating tumor
- cell free
- single molecule
- sensitive detection
- loop mediated isothermal amplification
- quantum dots
- risk assessment
- nucleic acid
- blood pressure
- real time pcr
- living cells
- circulating tumor cells
- high throughput
- cancer therapy
- hydrogen peroxide
- carbon nanotubes
- nitric oxide
- fluorescent probe
- energy transfer
- single cell