Synthesis of para-sulfonatocalix[4]arene-modified silver nanoparticles as colorimetric histidine probes

Article abstract of DOI:10.1039/b716270g

This Communication reports a novel colorimetric sensor to probe histidine in water based on para-sulfonatocalix[4]arene-modified silver nanoparticles; this highly selective sensor allows a rapid quantitative assay of histidine down to a concentration of 5 × 10^-6 M, providing a new tool for the direct measurement of histidine. The Royal Society of Chemistry.

Full text of DOI:10.1039/b716270g

View Article Online / Journal Homepage / Table of Contents for this issue
COMMUNICATION
www.rsc.org/chemcomm | ChemComm
Synthesis of para-sulfonatocalix[4]arene-modified silver nanoparticles as
colorimetric histidine probesw
Dejun Xiong, Mingliang Chen and Haibing Li*
Received (in Cambridge, UK) 22nd October 2007, Accepted 4th December 2007
First published as an Advance Article on the web 18th December 2007
DOI: 10.1039/b716270g
This Communication reports a novel colorimetric sensor to
probe histidine in water based on para-sulfonatocalix[4]arene-
modified silver nanoparticles; this highly selective sensor allows a
rapid quantitative assay of histidine down to a concentration of
5 Â 10À6 M, providing a new tool for the direct measurement
of histidine.
as well as for maintenance of the myelin sheaths that act as the
protector of nerve cells. It is manufactured in sufficient
quantities in adults, but children may, at some time, develop
a shortage of this important amino acid.14 For these reasons,
several analytical methods have been developed to detect His,
such as fluorescence and colorimetry.15
In this Communication, we report the synthesis of water
soluble pSC4-modified Ag NPs (pSC4-Ag NPs) and their
application as a novel colorimetric sensor for His.
Noble metal nanoparticles (NPs), especially of silver and gold,
have attracted much attention due to their remarkable optical,
electrical and chemical properties.1–3 In particular, ligand-
protected metal NPs have been increasingly explored as
analytical tools in many biological fields.4 The introduction
of organic ligands onto NP surfaces provides not only stability
to these nanoentities in different solvents, but also desirable
surface functionalities.5 Recently, noble metal NPs modified
with macrocyclic molecules have been some of the interesting
research topics. For example, Chan and co-workers reported
15-crown-5 functionalized Au NPs for the detection of potas-
sium ions in water.6 Kaifer and co-workers also synthesized
thiolated g-cyclodextrin-capped Au NPs for the recognition of
C60.7 Calixarenes are considered as the third class of host
molecules after crown ethers and cyclodextrins, and have
demonstrated outstanding complexation activity towards ions,
neutral molecules, etc.8 Pochini and co-workers synthesized
1,3-dialkoxycalix[4]arene-modified Au NPs to probe quatern-
ary ammonium cations in CDCl3.9 Unfortunately, an organic
medium was required for their analysis, thus restricting tre-
mendously its analytical potential. Therefore, it is a great
challenge to construct water soluble noble metal NPs modified
with calixarenes.
By reacting silver nitrate with sodium borohydride in the
presence of 1.0 equiv. of pSC4 at room temperature for only
5 min, pSC4-Ag NPs were obtained in water, and characterized
by transmission electron microscopy (TEM), FT-IR and UV-
vis spectroscopy. A TEM image shows that the modified NPs
are highly dispersed and uniform in aqueous solution, with a
diameter 8.0 Æ 1.0 nm (Fig. 1(a)). Fig. 2 shows the FT-IR
spectra of pure pSC4 and Ag NPs modified with pSC4.
Comparing the FT-IR spectra of pSC4 and pSC4-Ag NPs,
significant features can be seen: the peaks for SO3À at 1187 and
1049 cmÀ1, as found in pure pSC4, are shifted to 1178 and
À
1036 cmÀ1, respectively, which suggests that the SO3 groups
coordinate with the silver atoms on the surface of the Ag NPs.
The dramatic differences between the FT-IR spectra, espe-
cially for SO3À, indicate that the pSC4 is modified on the Ag
NPs. Similar results have been found in Fe3O4 and Cu2O NPs
modified with pSCn (n = 6, 8), respectively.11,12
The UV-vis spectra of pSC4-Ag NPs recorded after different
reaction times are shown in Fig. 3(a)–(c). An adsorption peak
emerges at 394 nm that originates from the surface plasmon
absorption of Ag NPs.16 The spectrum recorded after 5 min
has the narrowest full-width-at-half-maximum (fwhm), indi-
cating that the synthesized NPs are monodispersed and uni-
form. The pSC4-Ag NPs remain stable for at least one month.
To further estimate the stability of the pSC4-Ag NPs, we
compared them with mercaptoacetic acid-modified Ag NPs
Water soluble para-sulfonatocalix[n]arene (pSCn), which
can bind amino acids,10 has been employed to modify Fe3O4
and Cu2O NPs in water.11,12 Meanwhile, functionalized noble
metal NPs have been synthesized to probe various analytes.13
These findings motivated us to synthesize noble metal NPs
modified with pSCn, which may allow amino acids to be
probed in aqueous solution.
Among the twenty amino acids used as building blocks for
proteins, histidine (His) is one of the basic examples due to its
aromatic nitrogen-containing heterocyclic imidazole ring and
side chain. It is needed for the growth and the repair of tissue,
Key Laboratory of Pesticide and Chemical Biology (CCNU),
Ministry of Education, College of Chemistry, Central China Normal
University, Wuhan 430079, PR China. E-mail:
lhbing@mail.ccnu.edu.cn; Tel: +86 27 67866423
w Electronic supplementary information (ESI) available: Experimental
details and additional data. See DOI: 10.1039/b716270g
Fig. 1 TEM images of pSC4-Ag NPs (a) before and (b) after addition
of 10À4 M His. The scale bars are both 50 nm.
ꢀc
This journal is The Royal Society of Chemistry 2008
880 | Chem. Commun., 2008, 880–882

View Article Online
Fig. 2 FT-IR spectra of (a) pSC4 and (b) pSC4-Ag NPs.
(MA-Ag NPs), which were synthesized using quite a long
reaction time (7 h) under similar reduction reaction condi-
tions. A MA-Ag NP solution only remained stable for a week
(ESI, Fig. S1w). This indicates that pSC4-Ag NPs are more
stable in aqueous solution due to the macrocyclic effect, which
refers to the multidentate macrocyclic ligands modified on the
surface of the metal NPs increasing the thermodynamic stabi-
lity of the NPs compared to open chain ligands.17
Fig. 4 R (A493/A394) (top) and photographic images (bottom) of
pSC4-Ag NP solutions containing different amino acids. Typically,
1 mL of 10À4 M solutions of various amino acids were added to
4 mL pSC4-Ag NP solutions, and the combined solutions mixed well
for 30 min and then tested.
In order to investigate the molecular recognition ability of
pSC4-Ag NPs, a variety of amino acids were added to pSC4-Ag
NP solutions. Fig. 4 displays the color changes and R values
(A493/A394) of pSC4-Ag NP solutions after the addition of 10À4
M solutions of various amino acids. Over 30 min, the solution
containing His changed from yellow to red, with a dramatic
increase in the absorbance ratio A493/A394. However, the
addition of other amino acids had no effect on the color or
adsorption spectrum of pSC4-Ag NPs, which indicates that the
pSC4-Ag NPs responded selectively to His. This response can
be attributed to the pSC4-Ag NP aggregation induced by His,
which is supported by a TEM image (Fig. 1(b)). A schematic
of the aggregation process is shown in Fig. 5. pSC4 possesses
an electron-rich cyclic cavity that can fit an imidazole. There-
fore, pSC4 can bind the imidazole and amino residue of His via
host–guest, electrostatic and cation–p interactions. These
interactions between a His and two pSC4-modified Ag NPs
result in pSC4-Ag NPs tending to aggregate more easily than
the other amino acids tested.
Fig. 6 indicates the adsorption spectrum changes of pSC4-
Ag NPs after the addition of different concentrations of His
over 30 mins. A linear correlation exists between R and the
logarithm of the His concentration C over the range of 5 Â
10À6–10À3 M. The linear equation is as follows: R = 1.825 +
(0.334 Â log[C]) The limit of detection (3s) for His was
5 Â 10À6 M.
In conclusion, water soluble and stable para-sulfonato-
calix[4]arene-modified Ag NPs were prepared successfully.
The modified NPs could be utilized as a novel colorimetric
Fig. 3 UV-vis spectra of pSC4-Ag NPs recorded after: (a) 1, (b) 5 and
Fig. 5 Schematic representation of the His-induced aggregation of
pSC4-Ag NPs.
(c) 60 min, and MA-Ag NPs recorded after: (d) 4, (e) 7 and (f) 10 h.
ꢀc
This journal is The Royal Society of Chemistry 2008
Chem. Commun., 2008, 880–882 | 881

View Article Online
3 (a) B. M. Wile and M. Stradiotto, Chem. Commun., 2006, 4104; (b)
J. Shen, W. Shan, Y. H. Zhang, J. M. Du, H. L. Xu, K. N. Fan, W.
Shen and Y. Tang, Chem. Commun., 2004, 2880.
4 (a) J. D. Gibson, B. P. Khanal and E. R. Zubarev, J. Am. Chem.
Soc., 2007, 129, 11653; (b) E. M. Larsson, J. Alegret, M. Kall and
D. S. Sutherland, Nano Lett., 2007, 7, 1256; (c) D. K. Kim, K.
Kerman, M. Saito, R. R. Sathuluri, T. Endo, S. Yamamura, Y. S.
Kwon and E. Tamiya, Anal. Chem., 2007, 79, 1855.
5 (a) R. Shenhar and V. M. Rotello, Acc. Chem. Res., 2003, 36, 549;
(b) M. C. Daniel and D. Astruc, Chem. Rev., 2004, 104, 293; (c) M.
A. El-Sayed, Acc. Chem. Res., 2001, 34, 257; (d) K. G. Thomas and
P. V. Kamat, Acc. Chem. Res., 2003, 36, 888; (e) M. Sastry, M. Rao
and K. N. Ganesh, Acc. Chem. Res., 2002, 35, 847.
6 H. M. Rowe, S. P. Chan, J. N. Demas and B. A. DeGraff, Anal.
Chem., 2002, 74, 4821.
7 J. Liu, J. Alvarez, W. Ong and A. E. Kaifer, Nano Lett., 2001, 1,
57.
8 (a) C. D. Gutsche, Calixarenes Revisited, Royal Society of Chem-
istry, Cambridge, 1998; (b) H. B. Li, Y. Y. Chen and X. L. Yang,
Chin. J. Chem., 2005, 23, 891; (c) H. B. Li, Y. Y. Chen, Z. R. Zeng,
C. H. Xie and X. L. Yang, Anal. Sci., 2005, 21, 717; (d) H. B. Li, Y.
Y. Chen and S. L. Liu, J. Appl. Polym. Sci., 2003, 89, 1139; (e) H.
B. Li and Y. Y. Chen, React. Funct. Polym., 2003, 55, 171; (f) Y. Y.
Chen and H. B. Li, New J. Chem., 2001, 25, 340; (g) Y. Y. Chen
and H. B. Li, Chem. Lett., 2000, 1208.
9 A. Arduini, D. Demuru, A. Pochini and A. Secchi, Chem.
Commun., 2005, 645.
10 F. Perret, A. N. Lazar and A. W. Coleman, Chem. Commun., 2006,
2425.
Fig. 6 (a) The adsorption spectra of pSC4-Ag NP solutions with
various concentrations of His (0, 5 Â 10À6, 10À5, 5 Â 10À5, 10À4
,
5 Â 10À4 and 10À3 M). (b) The dependence of the R (A493/A394) values
of the pSC4-Ag NPs on increasing concentrations of His. Typically,
1 mL of various concentrations of His were added to 4 mL pSC4-Ag
NP solutions. The solutions were then mixed well for 30 min before
being tested.
11 M. L. Ben-Ishay and A. Gedanken, Langmuir, 2007, 23, 5238.
12 M. Chen, G. W. Diao and X. M. Zhou, Nanotechnology, 2007, 18,
275606.
probe for His, which allowed a rapid quantitative assay of His
down to a concentration of 5 Â 10À6 M.
13 (a) K. Aslan, J. R. Lakowicz and C. D. Geddes, Anal. Chim. Acta,
2004, 517, 139; (b) J. Zhang, D. Roll, C. D. Geddes and J. R.
Lakowicz, J. Phys. Chem. B, 2004, 108, 12210; (c) B. J. Kennedy,
R. Milofsky and K. T. Carron, Anal. Chem., 1997, 69, 4708; (d) K.
T. Carron and B. J. Kennedy, Anal. Chem., 1995, 67, 3353; (e) R.
Sulk, C. Chan, J. Guicheteau, C. Gomez, J. B. B. Heyns, R.
Corcoran1 and K. Carron, J. Raman Spectrosc., 1999, 30, 853.
14 (a) T. E. Creighton, Encyclopedia of Molecular Biology, Wiley,
New York, 1999, vol. 2, pp. 1147; (b) G. N. Chen, X. P. Wu, J. P.
Duan and H. Q. Chen, Talanta, 1999, 49, 319.
This work was financially supported by the National Nat-
ural Science Foundation of China (20602015 and 20772038),
the Program for Distinguished Young Scientists of Hubei
Province (2007ABB017) and the Program for Chenguang
Young Scientists of Wuhan (200750731283).
15 (a) Y. Y. Liu, M. G. Fan, S. X. Zhang, X. H. Sheng and J. N. Yao,
New J. Chem., 2007, 31, 1878; (b) J. F. Folmer-Andersen, V. M.
Lynch and E. V. Anslyn, Chem.–Eur. J., 2005, 11, 5319; (c) X. H.
Li, H. M. Ma, L. H. Nie, M. Sun and S. X. Xiong, Anal. Chim.
Notes and references
1 (a) B. A. Du, Z. P. Li and C. H. Liu, Angew. Chem., Int. Ed., 2006,
45, 8022; (b) B. A. Gorman, P. S. Francis, D. E. Dunstan and N.
W. Barnett, Chem. Commun., 2007, 395.
Acta, 2004, 515, 255; (d) M. A. Hortala, L. Fabbrizzi, N. Marcotte,
´
2 (a) O. Lioubashevski, V. I. Chegel, F. Patolsky, E. Katz and I.
Willner, J. Am. Chem. Soc., 2004, 126, 7133; (b) J. M. Wessels, H.
G. Nothofer, W. E. Ford, F. von Wrochem, F. Scholz, T.
Vossmeyer, A. Schroedter, H. Weller and A. Yasuda, J. Am.
Chem. Soc., 2004, 126, 3349.
F. Stomeo and A. Taglietti, J. Am. Chem. Soc., 2003, 125, 20.
16 M. Ji, X. Chen, C. M. Wai and J. L. Fulton, J. Am. Chem. Soc.,
1999, 121, 2631.
17 J. Liu, W. Ong, A. E. Kaifer and C. Peinador, Langmuir, 2002, 18,
5981.
ꢀc
This journal is The Royal Society of Chemistry 2008
882 | Chem. Commun., 2008, 880–882