2.4. Preparation and functioning of the sensing probe
For the electrochemical studies, a Potentiostat/Galvanostat
from Princeton Applied Research (Model 263A) having PS Lite
software were used, connected with a single compartment cell
with three electrodes (where counter as well as working electrode
is Pt wire and an Ag/AgCl electrode acts as a reference electrode
respectively). Initially, 3 mL Grp-β-CD solution (solvated in PBS,
maintained at pH of 7.4) was taken in the electrochemical cell.
2 mL, 10 mM Methylene Blue solution was then added and kept for
a while. As suggested earlier, MB molecules are expected to move
inside the cavity of the β-CD molecules, forming an inclusion
complex of Grp-β-CD-MB (the sensing probe). The sensing probe
was then centrifuged, separated and washed thoroughly to remove
the MB traces remaining on the surface. The residual probe
was transferred again to the electrochemical cell with 3 mL fresh
PBS solution, assuming it as a blank solution. The CV and DPV
measurements were carried out before and just after mixing with
sequential addition of stock cholesterol aliquots. CV plot was taken
at a scan rate of 10 mV/s, within the potential window of 0.6 to
0.6 V. DPV scan was taken with pulse height of 50 mV and pulse
width of 70 ms. Stock solution of cholesterol were added to it, in
such a manner that its final concentration in the system would
increased from 0 to 100 mM. Due to its higher binding affinity
towards β-CD, cholesterol molecules are expected to replace the
MB molecules, forming Grp-β-CD-cholesterol complex and the
extent of MB molecule moving out of the graphene–CD system,
would be detected by DPV and CV measurements after each
addition. Initially the sensing probe was characterized using Cyclic
Voltammetric (CV) measurements, to ensure the potential window
required for the DPV.
2.4. Preparation and functioning of the sensing probeFor the electrochemical studies, a Potentiostat/Galvanostatfrom Princeton Applied Research (Model 263A) having PS Litesoftware were used, connected with a single compartment cellwith three electrodes (where counter as well as working electrodeis Pt wire and an Ag/AgCl electrode acts as a reference electroderespectively). Initially, 3 mL Grp-β-CD solution (solvated in PBS,maintained at pH of 7.4) was taken in the electrochemical cell.2 mL, 10 mM Methylene Blue solution was then added and kept fora while. As suggested earlier, MB molecules are expected to moveinside the cavity of the β-CD molecules, forming an inclusioncomplex of Grp-β-CD-MB (the sensing probe). The sensing probewas then centrifuged, separated and washed thoroughly to removethe MB traces remaining on the surface. The residual probewas transferred again to the electrochemical cell with 3 mL freshPBS solution, assuming it as a blank solution. The CV and DPVmeasurements were carried out before and just after mixing withsequential addition of stock cholesterol aliquots. CV plot was takenat a scan rate of 10 mV/s, within the potential window of 0.6 to0.6 V. DPV scan was taken with pulse height of 50 mV and pulsewidth of 70 ms. Stock solution of cholesterol were added to it, insuch a manner that its final concentration in the system wouldincreased from 0 to 100 mM. Due to its higher binding affinitytowards β-CD, cholesterol molecules are expected to replace the
MB molecules, forming Grp-β-CD-cholesterol complex and the
extent of MB molecule moving out of the graphene–CD system,
would be detected by DPV and CV measurements after each
addition. Initially the sensing probe was characterized using Cyclic
Voltammetric (CV) measurements, to ensure the potential window
required for the DPV.
การแปล กรุณารอสักครู่..