Limits...
Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection

View Article: PubMed Central

ABSTRACT

A cyanide biosensor based on a pH-sensitive p-doped electrolyte-insulator-semiconductor (EIS) structure with an immobilised enzyme (cyanidase) is realised at the laboratory scale. The immobilisation of the cyanidase is performed in two distinct steps: first, the covalent coupling of cyanidase to an N-hydroxysuccinimide- (NHS) activated Sepharose™ gel and then, the physical entrapment of NHS-activated Sepharose™ with the immobilised cyanidase in a dialysis membrane onto the EIS structure. The immobilisation of the cyanidase to the NHS-activated Sepharose™ is studied by means of gel electrophoresis measurements and investigations using an ammonia- (NH3) selective electrode. For the electrochemical characterisation of the cyanide biosensor, capacitance/voltage and constant capacitance measurements, respectively, have been carried out. A differential measurement procedure is presented to evaluate the cyanide concentration-dependent biosensor signals.

No MeSH data available.


PhastGel Homogeneus 12.5 with silver stain (top) and dedicated gel scan in vertical direction (bottom) at y-position of 37.5 kDa in order to evaluate the immobilisation process of cyanidase to NHS-activated Sepharose™: sample S1 belongs to t = 0 h and sample S6 to t = 22 h 20 min.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3814860&req=5

f1-sensors-07-01415: PhastGel Homogeneus 12.5 with silver stain (top) and dedicated gel scan in vertical direction (bottom) at y-position of 37.5 kDa in order to evaluate the immobilisation process of cyanidase to NHS-activated Sepharose™: sample S1 belongs to t = 0 h and sample S6 to t = 22 h 20 min.

Mentions: Figure 1 (top) shows a photograph of the gel including standard proteins and the quantitative evaluation by means of a gel scan (bottom). As can be seen from the figure, the width of the band at 37.5 kDa has been reduced from sample S1 at the beginning of the immobilisation procedure to sample S7 at the end of the immobilisation process. Calculations of the peak area at 37.5 kDa have resulted in an amount of 11 mg (originally 27 mg) of cyanidase that has been covalently coupled to 2 ml of NHS-activated Sepharose™ (“cyanidase gel”) (comparison between sample S1 and sample S6) after an immobilisation time of 22 h and 20 min. The investigations also exhibit that the enzyme is not completely homogenously distributed in buffer solution (see e.g., sample S4 and sample S5). Nonetheless, a decreasing band width with increasing immobilisation time has been found that underlines the bonding of the cyanidase to the NHS-activated Sepharose™.


Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection
PhastGel Homogeneus 12.5 with silver stain (top) and dedicated gel scan in vertical direction (bottom) at y-position of 37.5 kDa in order to evaluate the immobilisation process of cyanidase to NHS-activated Sepharose™: sample S1 belongs to t = 0 h and sample S6 to t = 22 h 20 min.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814860&req=5

f1-sensors-07-01415: PhastGel Homogeneus 12.5 with silver stain (top) and dedicated gel scan in vertical direction (bottom) at y-position of 37.5 kDa in order to evaluate the immobilisation process of cyanidase to NHS-activated Sepharose™: sample S1 belongs to t = 0 h and sample S6 to t = 22 h 20 min.
Mentions: Figure 1 (top) shows a photograph of the gel including standard proteins and the quantitative evaluation by means of a gel scan (bottom). As can be seen from the figure, the width of the band at 37.5 kDa has been reduced from sample S1 at the beginning of the immobilisation procedure to sample S7 at the end of the immobilisation process. Calculations of the peak area at 37.5 kDa have resulted in an amount of 11 mg (originally 27 mg) of cyanidase that has been covalently coupled to 2 ml of NHS-activated Sepharose™ (“cyanidase gel”) (comparison between sample S1 and sample S6) after an immobilisation time of 22 h and 20 min. The investigations also exhibit that the enzyme is not completely homogenously distributed in buffer solution (see e.g., sample S4 and sample S5). Nonetheless, a decreasing band width with increasing immobilisation time has been found that underlines the bonding of the cyanidase to the NHS-activated Sepharose™.

View Article: PubMed Central

ABSTRACT

A cyanide biosensor based on a pH-sensitive p-doped electrolyte-insulator-semiconductor (EIS) structure with an immobilised enzyme (cyanidase) is realised at the laboratory scale. The immobilisation of the cyanidase is performed in two distinct steps: first, the covalent coupling of cyanidase to an N-hydroxysuccinimide- (NHS) activated Sepharose™ gel and then, the physical entrapment of NHS-activated Sepharose™ with the immobilised cyanidase in a dialysis membrane onto the EIS structure. The immobilisation of the cyanidase to the NHS-activated Sepharose™ is studied by means of gel electrophoresis measurements and investigations using an ammonia- (NH3) selective electrode. For the electrochemical characterisation of the cyanide biosensor, capacitance/voltage and constant capacitance measurements, respectively, have been carried out. A differential measurement procedure is presented to evaluate the cyanide concentration-dependent biosensor signals.

No MeSH data available.