Nanoparticles of molecularly imprinted polymer

A process for producing nanoparticles of molecularly imprinted polymers comprises: immobilising a template on a solid support; locating the supported template material in a reaction vessel having one or more flow inlets, one or more flow outlets, a cooler/heater and a radiation source arranged to irradiate the interior of the reaction vessel; passing a polymerisable composition into the vessel through one or more of the flow inlets; irradiating the reaction vessel s interior; ceasing the irradiation at a stage when polymerisation has generated nanoparticles with molecular weights of 500-1000000 Da; passing solvent through the vessel to wash out unreacted components of the polymerisable composition; and passing solvent through the reaction vessel such that at least some of the bound nanoparticles are separated from the immobilised template. A photoreactor comprising: a reaction vessel for holding a solid phase bearing an immobilised template species; a radiation source arranged to irradiate the interior of the reaction vessel; A fluidic system in communication with the reaction vessel for providing an inflow comprising polymerisable monomer(s) and an outflow containing synthesised nanoparticles; and a computer programmed and arranged for controlling the production process is also disclosed.