Colorimetric Detection of Thiols Using a Chromene Molecule

Huo, Fangjun; Sun, Yuanqiang; Jing, Su; Chao, Jianbin; Zhi, Haijuan; Yin, Caixia

doi:10.1021/ol901951h

Cited by 132 publications

(49 citation statements)

References 54 publications

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“…As one example, the high sensitivity of the absorption peak shift caused by addition of the thiol molecules (Fig. 4B), is comparable to what can be achieved with colorimetric organic dyes (42). The general concept of introducing a thin layer of differing conductivity from the core could also be useful in other areas such as surfaceenhanced Raman spectroscopy (SERS), fluorescence, energy harvesting, and even catalysis.…”

Section: Discussionmentioning

confidence: 83%

Reversing the size-dependence of surface plasmon resonances

Peng

McMahon

Schatz

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

435

436

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The size-dependence of surface plasmon resonances (SPRs) is poorly understood in the small particle limit due to complex physical/chemical effects and uncertainties in experimental samples. In this article, we report an approach for synthesizing an ideal class of colloidal Ag nanoparticles with highly uniform morphologies and narrow size distributions. Optical measurements and theoretical analyses for particle diameters in the d ≈ 2-20 nm range are presented. The SPR absorption band exhibits an exceptional behavior: As size decreases from d ≈ 20 nm it blue-shifts but then turns over near d ≈ 12 nm and strongly red-shifts. A multilayer Mie theory model agrees well with the observations, indicating that lowered electron conductivity in the outermost atomic layer, due to chemical interactions, is the cause of the red-shift. We corroborate this picture by experimentally demonstrating precise chemical control of the SPR peak positions via ligand exchange.T he ability to control surface plasmon resonances (SPRs) in metal nanostructures is critical for achieving advances in many areas, including chemical and biological sensing, imaging, optoelectronics, energy harvesting and conversion, and medicine (1-12). Metal nanoparticles (NPs), particularly those of the noble metals (e.g., Au and Ag) that exhibit strong SPRs, have been the focus of much work (13-17). SPRs have intense and broad optical absorption bands that arise from coherent oscillations of conduction electrons near the NP surfaces. In general, SPRs are influenced by their size, morphology, composition, surface chemistry, and surrounding environment (18,19). However, the size-dependence of SPRs that is important for the aforementioned applications (1-12) is poorly understood in the small particle limit due to complex physical and chemical effects as well as uncertainties in experimental samples. Here, we report an approach for synthesizing an ideal class of colloidal Ag NPs with highly uniform morphologies and narrow size distributions. The SPR absorption band for particles with diameters, d, in the range of 2-20 nm is found to exhibit an exceptional behavior: As size decreases from d ≈ 20 nm it blue-shifts but then turns over near d ≈ 12 nm and strongly red-shifts. We have developed a multilayer Mie theory model and the corresponding calculation results agree well with the observations, indicating that the lowered electron conductivity in the outermost atomic layer, due to chemical interactions, is the cause of the red-shift. We corroborate this picture by experimentally demonstrating precise chemical control of the SPR peak positions via ligand exchange. Such chemical control of the NP surface layer may provide a promising strategy for sensitively probing species strongly adsorbed (or bonded) to the NPs.For metal NPs with d or structural features larger than 20 nm, often a purely continuum-level, classical electrodynamics picture suffices for interpretation or prediction of their optical properties. In this approach the bulk dielectric constants for the vario...

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Section: Discussionmentioning

confidence: 83%

Reversing the size-dependence of surface plasmon resonances

Peng

McMahon

Schatz

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

435

436

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show abstract

“…105 The bathochromic shift of the absorption band was explained by a thiol-mediated cleavage of the electron-withdrawing sulfonyl group of The second example uses a chromene derivative (67) (Figure 23). 106 In the presence of cysteine (HEPES, pH 7.0), the absorption peak at 292 nm of probe 67 decreases and a new peak appeared at 405 nm (change in colour from colourless to yellow). The effect caused by Cys was highly selective and for instance the authors report that solutions containing other amino acids (Ala, Arg, Asn, Asp, Gln, Glu, Gly, …”

mentioning

confidence: 99%

Chromogenic and fluorogenic chemosensors and reagents for anions. A comprehensive review of the year 2009

2011

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“…To this end, various analytical procedures (e.g., electrochemistry [9,10], high-performance liquid chromatography [11], fluorimetric [12], and spectrophotometry [13]) were developed to detect of the biological thiols. Beside of their good capabilities for detection of different thiols, these methods often suffer from a variety of disadvantages, such as use of sophisticated, expensive instruments and time consuming techniques also require derivatization with synthetic chemodosimeters [14,15].…”

Section: Introductionmentioning

confidence: 99%