,2008,28 (12) :7211 Metallurgical Analysis,2008,28 (12) :7211 :1000-7571 (2008) 12-0007 - 05 CdTe ( ),,, 3 (, 110004) :, 100, Cd Te Hg 2 + Cd Te,Cd Te Hg 2 + p H 7. 5, (Cd 2 + ) 6. 0 10-5 mol/ L,Hg 2 + 0. 241510 g/ L, 01999 2,0. 07g/ L (3 ),5. 8 %, 95. 0 %96. 0 % : ;; ; ; :O657131 :A,, [1 ], [2 ] [3 ] [4 ] [526 ],,, [728 ] ( quant um dot s, QDs) [9210 ],, [11212 ],, CdSe/ ZnS Hg 2 +, 3g/ L [13 ],,, Cd Te Hg 2 +,0. 07 g/ L, Hg 2 + 1 1. 1 L S255 ( Perkin Elmer ) ; DF2 101S ( ) ;SZ293 ( ) ;p HS23C ( ) :99. 999 %, ;( CdCl2 2. 5 H2 O) :, ; :, ) ; : > 9815 %, ; :1. 0 g/ L,; Tris, [14 ] 1. 2 1. 2. 1 Cd Te,,,,, :2007-12 - 30 : (20675011) :(1983 - ),,, :,,, Tel :024283681343,E2mail :xushukun46 @126. com 7
L I Meng2ying, ZHOU Hua2meng, DON G Zai2zheng,et al. Cysteine2capped Cd Te quantum dot s as fluorescence probes for determination of mercury ( ). Metallurgical Analysis,2008,28 (12) :7211 2, (), 100, Cd Te,,, 1. 2. 2 Hg 2 +,50 L 10 ml, 0. 5 ml, Hg 2 +,,, 5 min, 2 2. 1 2. 1. 1, Hg 2 +,,, ;,,,,,,, 1, ( 2. 5 6. 0 10-5 mol/ L),,, Cd Te,,,,, Hg 2 +, Cd Te 6. 0 10-5 mol/ L 2. 1. 2 p H, 3, ( HBO3 + Na2B4 O7 ), Tris ( Tris + HCl) ( PBS, Na2 HPO4 + KH2 PO4 ) p H, : PBS, Cd Te p H, p H (5. 5 8 1 Fig. 1 The relationship between the concentration and the fluorescence intensity of QDs 17,6. 0,5. 5,5. 0,4. 5,4. 0,3. 5,3. 0, 2. 5 10-5 mol/ L QDs concentration for curve 17 are 61 0,51 5,510,415,410, 315,310,215 10-5 mol/ L, respectively. 13. 0) Hg 2 +, 2 2 2 : p H, Cd Te,,, [15 ] p H 7. 0,p H Cd Te, Hg 2 + p H, 2 1 2, Hg 2 + p H Cd Te, p H 7. 5 PBS, PBS, 3 ( 0. 000 25 0. 004 mol/ L),,,PBS 0. 002 5 mol/ L 2. 1. 3, : Hg 2 + Cd Te 5 min,,,, (20 ) :,
,,,. Cd Te ( ).,2008,28 (12) :7211 Cd Te [17 ] 2 ph CdTe Fig. 2 The action curves of ph value on CdTe QDs QDs : 6. 0 10-5 mol/ L ; Hg 2 + : 7. 38 g/ L ; PBS : 0. 002 5 mol/ L. 3 Fig. 3 Effect of buffer concentration QDs :6. 0 10-5 mol/ L ; Hg 2 + :7. 38g/ L ;p H 7. 5. CdTe PBS,, Hg 2 +, 2. 2 Hg 2 + CdTe 4, Hg 2 + Cd Te, Hg 2 +, Cd Te,5 nm Cd Te Hg 2 +, Cd Te Hg 2 +,,Hg 2 + ;, Hg 2 + [16 ] Hg 2 + Cd Te, Hg 2 + 2Cd Te 4 Hg 2 + CdTe Fig. 4 Effect of the concentration of Hg 2 + pared CdTe QDs on as2pre2 15 Hg 2 + 0,3. 69,7. 38,11. 07,14. 76 g/ L ;:6. 0 10-5 mol/ L ; PBS :0. 002 5 mol/ L Hg 2 + concentration of curve 1-5 are 0,3. 69,7. 38,11. 07, 14. 76 g/ L, respetively. QDs : 6. 0 10-5 mol/ L ; PBS : 01002 5 mol/ L. 2. 3, 1, 2. 4,,Hg 2 + 0. 2415. 0 g/ L,Cd Te Hg 2 + 0. 999 2, F = F0 - F = 4. 27 + 18. 92( Hg 2 +, g/ L ) :LOD = 3 S0 / K ( LOD ; S0 ; K ) Hg 2 + 0. 07g/ L 7. 38g/ L 11, 0. 84 % 3 2. 5 ml ( ) ( ) Hg 2 +, Hg 2 +,, 2 9
L I Meng2ying, ZHOU Hua2meng, DON G Zai2zheng,et al. Cysteine2capped Cd Te quantum dot s as fluorescence probes for determination of mercury ( ). Metallurgical Analysis,2008,28 (12) :7211 Co2existing ions Al 3 + Ba 2 + Fe 3 + Cu 2 + Cd 2 + Pb 2 + As 3 + : Hg 2 + (g/ L) Ion concentration 54 137 56 6. 4 112 207 15 1 Table 1 Effect of co2existing ions on fluorescence intensity ( %) Change of fluorescence intensity - 0. 2 + 0. 3-4. 4-5. 2-1. 7 + 2. 9-3. 5 Co2existing ions Mn 2 + Zn 2 + Mg 2 + Bi 2 + Ca 2 + N H + 4 (g/ L) Ion concentration 10 325 144 209 40 360 ( %) Change of fluorescence intensity,4. 0g/ L ; PBS,0. 002 5 mol/ L,p H 7. 5 ;6. 0 10-5 mol/ L (Note : Hg 2 +,4. 0g/ L ; PBS,0. 002 5 mol/ L,p H 7. 5 ;QDs,6. 0 10-5 mol/ L. ) Water sample (g/ L) Found in test solution 2-5. 0 + 5. 6-4. 9-0. 3-5. 5-4. 5 Table 2 Determination results of mercury in sample n = 7 (g/ L) Found in water sample ( %) RSD (g/ L) Added ( %) Recovery 1 # - - - 4. 00 95. 0 2 # 0. 37 1. 5 5. 5 4. 00 96. 0 : [1 ],. 22 [J ]. (Metallur2 gical Analysis), 2006, 26 (3) : 15217. [2 ],,,. 2 [J ]. ( Studies of Trace Element s and Health),2002,19 (3) :47249. [3 ]. [J ]. (Chemical Analysis and Meterage),2002,11 (5) : 24225. [4 ],. [J ]. ( Spectronic Instruments & A2 nalysis),2006, (123) :76279. [5 ]. 2 [J ]. ( Southwest Water & Wastewater), 2008,30 (1) :44245. [ 6 ] Yang Y K, Yook K Y, Tae J A. Rhodamine2based fluorescent and colorimetric hemodosimeter for the rapid detection of Hg 2 + ions in aqueous media [J ]. J. Am. Chem. Soc., 2005, 127 (48) : 16760216761. [7 ] Cha M Y, Czarmik A W. Fluorometric chemodosime2 try mercury ( ) and silver ( I) indication in water via enhanced fluorescence signaling [ J ]. J. Am. Chem. Soc., 1992, 114 (24) : 970429705. [8 ] Zheng Z H, Qian L X, Yuan F F, et al. Switching the recognition preference of rhodamine B spirolactam by replacing one atom : design of rhodamine B thio2 10 hydrazide for recognition of Hg ( ) in aqueous solu2 tion [J ]. Organ. Lett., 2006, 8 (4) : 8592861. [9 ] Chan W C W,Nie S M. Quantum dot bioconjugates for ultrasensitive nonisotopic detection [ J ]. Science, 1998, 281 (5385) : 201622018. [ 10 ] Larson D R, Zipfel W R, Williams R M, et al. Wa2 ter2soluble quantum dot s for multiphoton fluorescence imaging in vivo [J ]. Science, 2003, 300 :143421436. [11 ] Bruchez M J, Moronne M, Alivisatos A P, et al. Semiconductor nanocrystals as fluorescent biological labels [J ]. Science, 1998, 281 (5385) : 201322016. [12 ] Li M Y, Ge Y X, Chen Q F, et al. Hydrothermal synthesis of highly luminescent Cd Te quantum dots by adjusting precursors concentration and their conjunc2 tion with BSA as biological fluorescent probes [ J ]. Talanta, 2007, 72 : 89294. [13 ] Li H B, Zhang Y, Wang X Q, et al. Calixarene capped quantum dots as luminescent probes for Hg 2 + ions [J ]. Mater. Lett., 2007 (61) : 147421477. [14 ],. ( Experimental Technology in Biochemistry) [ M ]. :,2005, 2912298. [15 ] Huang C P, Li Y K, Chen T M. A highly sensitive system for urea detection by using CdSe/ ZnS core2 shell quantum dot s [ J ]. Biosens. and Bioelectron., 2007, 22 (8) : 183521838. [16 ] Chen J L, Gao Y C, Xu Z B, et al. A novel fluores2 cent array for mercury ( ) ion in aqueous solution with f unctionalized cadmium selenide nanoclusters
,,,. Cd Te ( ).,2008,28 (12) :7211 [J ]. Anal. Chim. Acta, 2006, 577 : 77284. [17 ] Kim Y J, Johnson R C, Hupp J T. Gold nanoparti2 cle2based sensing of spectroscopically silent heavy metal ions [J ]. Nano Lett., 2001, 1 : 1652167. Cysteine2capped CdTe quantum dots as fluorescence probes for determination of mercury( ) L I Meng2ying, ZHOU Hua2meng, DON G Zai2zheng, XU Shu2kun (Department of Chemistry, Northeastern University, Shenyang 110004, China) Abstract : Cd Te quant um dot s (QDs) that show selective actions on metal ions were prepared by means of cysteine as modifying agent in aqueous solution at 100. The Cd Te quantum dot s were used as fluorescence probes for t he quantitative determination of trace amount s of Hg ( ) ions based on t he evident quenching action of Hg 2 + on t he fluorescence of QDs. When t he concentration of QDs was 610 10-5 mol/ L (representing in t he concentration of Cd 2 + ) in the p hosp hate buffer at p H 7. 5, the de2 gree of fluorescence quenching was linear wit h Hg ( ) mass concentration in t he range of 0. 24-15. 0 g/ L, with a linear correlation coefficient of 01999 2. The detection limit for Hg ( ) was 0. 07g/ L. The p roposed met hod was successf ully applied to the analysis of two real samples wit h t he RSD of 5. 8 % and recovery of 95. 0 % - 96. 0 %. Key words : cysteine ; quant um dot s ; fluorescence probe ; fluorescence quenching ; mercury China N IL Research Center fo r Proficiency Testing (N IL),2006 8 (No. CNAS P T0002), ISO/ IEC 43-1997IL AC G13 : 2000,,,, 200,62 6800 /, 48 535 /,, 2008, 33, 21 (http :/ / www. nil. org. cn) : 76 14, :100081 : : (010) 62187209/ 6287/ 1165 : (010) 62181163 E2mail : P T @analysis. org. cn / N IL @analysis. org. cn 11