Differential calixarene receptors create patterns that discriminate glycosaminoglycans

On account of the challenge of discriminating glycosaminoglycans (GAGs) via optical methods, we designed a fluorescence displacement sensing array. The sensing array is composed of four reporter pairs, where four positively charged calixarene derivatives act as receptors, and eosin Y as the reporter dye. The complexation of calixarenes quenches the fluorescence of the dye, and thereby, the competitive complexation of the analytes gives rise to fluorescence regeneration, achieving the switch-on sensing. By implementing an indicator displacement assay of four reporter pairs towards six GAGs, we obtained fluorescence response patterns for each GAG. The subsequent chemometric analysis makes the fluorescence discrimination of GAGs well realized. Besides the sensing selectivity, the present reporter pairs also exhibit high sensitivity.