forms a self assembled mono layer 12 of chiral molecules the substrate can also be formed by any other material e g a different metal or a semiconductor unpolarised electrons 16 ejected from the gold surface produced by linearly polarised light 18 incident from the monolayer side are transmitted and can be analyzed most of the electrons 20 transmitted through the monolayer 12 are spin polarised spin orientation depends on the enantiomer used in the monolayer it is well known that spin polarised photoelectrons are readily generated from magnetic substrates or when circularly polarised light ejects electrons from substrates with large spin orbit coupling since an organic chiral layer on a non magnetic metal surface is not likely to be self magnetized one expects that photoelectrons ejected from such a layer with unpolarised light will not be spin polarised the present invention however shows exceptionally high polarisation of electrons which are ejected from surfaces coated with self assembled monolayer of double stranded dna independent of the polarisation of the incident light it has previously been shown that the photoelectron yield from self assembled monolayers of chiral molecules on gold depends on the circular polarisation of the exciting light as well as the voltage across the layer and its handedness the spin polarisation of the electrons was not measured and indications for spin dependent transmission were only inferred from the dependence of the total electron yield on the circular polarisation of the incident photons these studies could not determine whether or not the ejected electrons are spin polarised when the incident photons are unpolarised or linearly polarised furthermore the observed effect may result from circular dichroism namely that the absorption of.