Biomarkers have been used for diagnosis of disease and other conditions for many decades, utilising a wide variety of analyte types. Furthermore, there are a wide variety of commercially available laboratory and 'point of care' (PoC) devices, many of which are in widespread clinical use; for example, glucose monitors and lateral-flow pregnancy tests. These, in general, use readily available patient samples (i.e. blood, saliva and urine), employing minimally invasive collection procedures. Development of other disease-specific biomarkers for application to PoC or 'near patient' devices are a focus of intense interest in a number of complex infectious disease areas where there is a clear clinical need for improved diagnostics (e.g. sepsis, tuberculosis, etc.). Many new biomarkers are emerging from clinical studies across multiple areas with potential for utility in disease diagnosis. The purpose of this study is to undertake a review of the critical issues in the development of clinically useful PoC devices. Furthermore, the authors discuss the issues and bottlenecks for validation and transition of new biomarkers into PoC diagnostics.