title: Off-on phosphorescence assay of heparin via gold nanoclusters modulated with protamine.
abstract: A sensitive and selective phosphorescence "turn-off-on" nanosensor to detect heparin by gold nanoclusters (Au-NCs) modulated with protamine was developed. The carboxyl groups on the surface of Au-NCs can interact with amino groups in protamine via electrostatic interactions and hydrogen bonding to induce the aggregation of Au-NCs, which results in the photoluminescence to "turn-off". However, in the presence of heparin, protamine prefers to combine with heparin to release Au-NCs, which results in the photoluminescence to "turn-on". The photoluminescence lifetime measurements demonstrate that the photoluminescence belongs to phosphorescence, and that the quenching progress is dynamic. The concentration of heparin can be determined by measuring the Au-NCs phosphorescence recovery. The linear response range was obtained from 0.006 to 25.0 μg mL(-1) with the detection limit of 6 ng mL(-1). Moreover, the proposed phosphorescence nanosensor was used to detect heparin in fetal bovine serum samples with satisfactory results.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China. Electronic address: snding@seu.edu.cn.
authors.forename: Shou-Nian
authors.initials: SN
authors.lastname: Ding
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
authors.forename: Chun-Mei
authors.initials: CM
authors.lastname: Li
authors.affiliation: School of Public Health, Nantong University, 226019 Nantong, Jiangsu, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Bao
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D006046:Gold / Q000737:chemistry; D006493:Heparin / Q000302:isolation & purification*; D008163:Luminescent Measurements / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D011479:Protamines / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry
chemical_list: D011479:Protamines; D012710:Serum Albumin, Bovine; D006046:Gold; D006493:Heparin
keywords: Gold nanoclusters; Heparin; Phosphorescence; Protamine