Integration of dialysis, reaction and detection

Sensors based on integrated dialysis, reaction and detection differ from those described in Section 4.3.1 in the fact that a (bio)chemical reaction takes place after separation (simultaneously with detection). They thus fit the generic configuration depicted in Fig. 5.1. A. Some of the ingredients of such a reaction may be immobilized at the sensing microzone, even though the reaction may also take place in the solution passed through it. 

The sample, whether aspirated or injected into a carrier stream, is circulated through these sensors, which can be arranged in two main ways 

The dialysis membrane employed is usually hydrophilic and isolates two aqueous solutions in a static or dynamic regime depending on the particular purpose. While these sensors are formally similar to those discussed in the previous section, it is molecules or ions that are separated (by virtue of a concentration gradient), the process being aided both by the dynamic character of the acceptor solution and the reaction involved, which removes the species transferred across the membrane. 

As with sensors based on a triply integrated process involving gas diffusion, there are few reported examples of sensors integrating dialysis, reaction and detection. There follows a description of die most salient examples based on the ingredient of the (bio)chemical reaction that is dialysed at the sensing micro2one. 

---