The present invention relates to a method for detection, identification, and/or quantification of one or more microbes, microbial peptides, or compounds of microbial origin, comprising the steps of: (a). contacting an object, a substance, or a sample with a luminescent conjugated oligothiophene (LCO); (b). detecting at least one signal of the luminescent conjugated oligothiophene (LCO) of a); and (c). based on said at least one detected signal in b), determining the presence, identity, and/or quantity of the one or more microbes, microbial peptides, or compounds of microbial origin on said object or in said sample. The present invention further relates to diagnostics and a method of diagnosis of microbes, microbial peptides, or compounds of microbial origin.