Rational design and bioimaging application of cholesterol conjugated fluorescence probe for Cu2+ detection

Abstract To improve the sensitivity and detection limit of probe, we made good use of the advantage of 6-carboxyrhodamine to design a new cholesterol-conjugated fluorescent probe Chol-6RN for Cu2+ detection. The probe Chol-6RN exhibits a sensitive response towards Cu2+ by fluorescence spectrum in aqueous solution. The linearity of Chol-6RN is from 5 μM to 40 μM of Cu2+ with an excellent linear correlation (R2 = 0.99110) and the detection limit for Cu2+ is 1.12 μM, they are better than the control probe Chol-RN. The MTT assay indicates that Chol-6RN is negligible cytotoxicity to HeLa cells after 24 h at a concentration less than 30 μM. The cell imaging displays that Chol-6RN is capable of detecting Cu2+ in live cells and the sensibility of Chol-6RN is better than Chol-RN.