Heavy metal ions detection in solution, in sol-gel and with grafted porphyrin monolayers

被引：56

作者：

Delmarre, D ^{[1
]}

Méallet, R ^{[1
]}

Bied-Charreton, C ^{[1
]}

Pansu, RB ^{[1
]}

机构：

[1] ENS, PPSM, CNRS, URA 1906, F-94235 Cachan, France

来源：

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY | 1999年 / 124卷 / 1-2期

关键词：

porphyrin; sol-gel; multi-layer; heavy metal; sensor;

D O I：

10.1016/S1010-6030(99)00046-5

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The detection of heavy metal ions - Hg2+, Pb2+, Cd2+ - by a free base porphyrin, 5,10,15,20-tetra(4-N-methylpyridyl)porphyrin (TMPyP), was studied. The porphyrin was either adsorbed in sol-gel matrix (TMOS) or grafted on glass surfaces. Detection limit was 10(-7) mol/l for mercury and cadmium, and 10(-5) mol/l for lead. Apparent association constants were calculated at pH = 7: pK (Cd2+) = -5.2; pK (Pb2+) = -4; and at pH = 4 pK (Hg2+) = -5.7. Both the shift of the Soret band and the change in fluorescence lifetime enabled the identification of the metal ions. In sol-gel, detection limits were found to be 10(-3) mol/l but 90% of the metal salts were trapped by the matrix. In sol-gel we have shown that the ions were pumped by the matrix at a concentration of 1.5 x 10(-5) mol/ml of sol-gel. The sol-gel limits both the reaction time and the detection threshold. No such effect is observed for grafted monolayers. A reaction time of 30 min and a detection limit of 10(-6) mol/l were measured for Hg2+ salts. (C) 1999 Elsevier Science S.A. All rights reserved.

引用

页码：23 / 28

页数：6

共 23 条

[1] Fluorescence quenching and complexation behaviour of tetraphenylporphyrin with some divalent metal ions [J].