Red emitting human serum albumin templated copper nanoclusters as effective candidates for highly specific biosensing of bilirubin.

In this paper, we report a new type of human serum albumin (HSA) stabilized red emissive copper nanoclusters (HSA-CuNCs) were prepared at room temperature and HSA-CuNCs were applied to identify the bilirubin in human urine and blood serum samples. The emission characteristics of synthesized HSA-CuNCs were pH responsive to that the intensity of emission enhanced quickly with varying the pH range from 12 to 6. Emission spectral signal of HSA-CuNCs was found as reduced well with the raise in the amounts of bilirubin attributed to strong binding attraction leads to the non-fluorescent complex formation of HSA-CuNCs with bilirubin. Due to the strong affinity between the nanoprobe and analyte, the red emissive HSA-CuNCs illustrates more specific for the detection bilirubin over the different potential interfering molecules. Two good linear relationships were distinguished the relative emission intensity of HSA-CuNCs versus bilirubin concentrations range from 1.25 × 10-6 to 7.50 × 10-6 M and 5.00 × 10-6 to 2.875 × 10-5 M with lowest limit of detection was determined as 35.00 × 10-9 M and 145.00 × 10-9 M (S/N = 3), respectively. Furthermore, this methodology was effectively used in the quantification of bilirubin in clinical (real) samples. In addition, this fluorometric method offers cost-effective, easy, highly specific and ultrasensitive optical platform for the determination of bilirubin.