Procedure for the determination of cocaine using an enzymatic biosensor

New and innovative aspects

The determination of cocaine has been carried out habitually using techniques very expensive chromatography. It is also a direct, fast, simple and inexpensive technique.

Main advantages of its use

The construction process by screen printing basically involves three stages consisting of the sequential deposition of the different inks and their subsequent curing. The first stage consists of the deposition of the graphite ink (Electrodag 407A) on the polyester substrate and its subsequent curing at 120 ºC for 30 min. The substrate, which already contains the motifs printed on it, is then properly aligned graphite ink, and the screen that defines the reference electrode. Ag / AgCl ink (Electrodag 6037 SS) is deposited, and cured under the same conditions.
Finally, and in order to define the electrochemically active area according to the design of figure 1, a last layer of an insulating ink is printed with the help of a third pattern, leaving free the upper part of the conductive bases of Ag to make the corresponding electrical connections.

Specifications

A device has been constructed containing three screen-printed electrodes. Two of the electrodes, silk-screened with carbon paste, will act as working electrodes, another silk-screened with an Ag / AgCl ink, it will act as a reference electrode and the third, also carbon, as a counter or auxiliary electrode.
Figure 1.- Designs made for the manufacture of the serigraphic sensors: auxiliary electrode (black), reference electrode (gray), working electrode (red).
Figure 2.- Images of the screens used in the construction of the serigraphic electrodes:
definition of the conductive paths and the working and auxiliary electrodes in carbon (A), definition of the reference electrode in Ag / AgCl (B) and definition of the insulating material (C).

Applications

Of great interest for the determination of this substance in routine controls of biological samples. Equally useful for determining the purity of drug samples.
Companies related to doping control.

Intellectual property status

Protected by patent P201000738

Current development status

Developed but not commercialized.

Desired business relationship

Commercial Agreement, License Agreement, Technical Cooperation: further development; Technical Cooperation: testing new applications; Technical Cooperation: adaptation to specific needs.