Antifouling Surface Chemistries to Minimize Signal Interference from Biological Matrices in Biosensor Technology
Upon contact with biofluids, artificial materials spontaneously acquire a layer of various species on their surface (most notably proteins). In biosensor technology, the issue is that of ‘non-specific adsorption’ (NSA) on sensing platforms of the multi-components of complex biological matrices, which generates an often overwhelming interference signal that prevents the detection, not to mention the quantification, of target analytes present at considerably lower concentration – up to several orders of magnitude. To alleviate this recurrent problem, this major technical hurdle to biosensor development, considerable research efforts have been devoted to engineer antifouling organic coatings. The present chapter first comprehensively identifies the state-of-the-art surface chemistries (self-assembled monolayers, polymer films/brushes) developed to minimize fouling surface coverage down to a few ng cm−2 from eight biological media (blood plasma, blood serum, cell lysate, cerebrospinal fluid, egg, milk, saliva, and urine), whether of human or animal origin. Described next is the successful transfer of such stealth technology into biosensor applications to combat NSA. Also discussed in this chapter is the dependence of the antifouling performance of molecular adlayers on the inherent compositional variability of real-life biosamples – a concern that is rarely touched upon but of utmost importance in the realm of bioanalysis.