Rapid assessment of DNA damage induced by polystyrene nanosphere suspension using a photoelectrochemical DNA sensor  

作　　者：ZHANG BinTian DU Xin JIA SuPing HE JunHui GUO LiangHong 

机构地区：[1]State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China [2]Functional Nanomaterials Laboratory and Key Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beifing 100080, China

出　　处：《Science China Chemistry》2011年第8期1260-1265,共6页中国科学（化学英文版）

基　　金：supported by the National Basic Research Program of China (2011CB936001);the National Natural Science Foundation of China (20825519, 20890112 & 20921063);Beijing Municipal Education Committee (KZ201110005006)

摘　　要：Nanomaterials have been used increasingly in a wide variety of applications, and some of them have shown toxic effects on experimental animals and cells. In this study, a previously established photoelectrochemical DNA sensor was employed to rapidly detect DNA damage induced by polystyrene nanosphere （PSNS） suspensions. In the sensor, a double-stranded DNA film was assembled on a semiconductor electrode, and a DNA intercalator, Ru（bpy）2（dppz）2＋ （bpy = 2,2＇-bipyridine, dppz = dipyrido[3,2-a：2＇,3＇-c]phenazine） was used as the photoelectrochemical signal indicator. After the DNA-modified electrode was exposed to 2.0 mg/mL PSNS suspension, photocurrent of DNA-bound Ru（bpy）2（dppz）2＋ decreased by about 20%. The decrease is attributed to the chemical damage of DNA and consequently less binding of Ru（bpy）2（dppz）2＋ molecules to the electrode. Gel electrophoresis of DNA samples incubated with PSNS suspension confirmed DNA damage after the chemical exposure. However, in both photoelectrochemical and gel electrophoresis experiments, extensively washed PSNS did not induce any DNA damage, and the supernatant of PSNS suspension exhibited comparable DNA damage as the unwashed PSNS suspension. Furthermore, UV-visible absorption spectrum of the supematant displayed a pattern very similar to that of styrene oxide （SO）, a compound which has been shown to induce DNA damage by forming covalent DNA adducts. It is therefore suggested that styrene oxide and other residual chemicals in the PSNS may be responsible for the observed DNA damage. The results highlight the importance of full characterization of nanomaterials before their toxicity study, and demonstrate the utility of photoelectrochemical DNA sensors in the rapid assessment of DNA damage induced by chemicals and nanomaterials.Nanomaterials have been used increasingly in a wide variety of applications, and some of them have shown toxic effects on experimental animals and cells. In this study, a previously established photoelectrochemical DNA sensor was employed to rapidly detect DNA damage induced by polystyrene nanosphere (PSNS) suspensions. In the sensor, a double-stranded DNA film was assembled on a semiconductor electrode, and a DNA intercalator, Ru(bpy)2(dppz)2+ (bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine) was used as the photoelectrochemical signal indicator. After the DNA-modified electrode was exposed to 2.0 mg/mL PSNS suspension, photocurrent of DNA-bound Ru(bpy)2(dppz)2+ decreased by about 20%. The decrease is attributed to the chemical damage of DNA and consequently less binding of Ru(bpy)2(dppz)2+ molecules to the electrode. Gel electrophoresis of DNA samples incubated with PSNS suspension confirmed DNA damage after the chemical exposure. However, in both photoelectrochemical and gel electrophoresis experiments, extensively washed PSNS did not induce any DNA damage, and the supernatant of PSNS suspension exhibited comparable DNA damage as the unwashed PSNS suspension. Furthermore, UV-visible absorption spectrum of the supernatant displayed a pattern very similar to that of styrene oxide (SO), a compound which has been shown to induce DNA damage by forming covalent DNA adducts. It is therefore suggested that styrene oxide and other residual chemicals in the PSNS may be responsible for the observed DNA damage. The results highlight the importance of full characterization of nanomaterials before their toxicity study, and demonstrate the utility of photoelectrochemical DNA sensors in the rapid assessment of DNA damage induced by chemicals and nanomaterials.

关 键 词：NANOMATERIAL TOXICITY DNA damage sensor 

分 类 号：TQ325.2[化学工程—合成树脂塑料工业] TP212.3[自动化与计算机技术—检测技术与自动化装置]