Moleculary imprinted polymers with metalloporphyrin-based molecular recognition sites coassembled with methacrylic acid.
A diastereoselective molecularly imprinted polymer (MIP) for (-)-cinchonidine, PPM(CD), was prepared by the combined use of methacrylic acid and vinyl-substituted zinc(II) porphyrin as functional monomers. Compared to MIPs using only methacrylic acid or zinc porphyrin as a functional monomer, PM(CD) and PP(CD), respectively, PPM(CD) showed higher binding ability for (-)-cinchonidine in chromatographic tests using the MIP-packed columns. Scatchard analysis gave a higher association constant of PPM(CD) for (-)-cinchonidine (1.14 x 10(7) M(-1)) than those of PP(CD) (1.45 x 10(6) M(-1)) and PM(CD) (6.78 x 10(6) M(-1)). The affinity distribution of binding sites estimated by affinity spectrum analysis showed a higher percentage of high-affinity sites and a lower percentage of low-affinity sites in PPM(CD). The MIPs containing a zinc(II) porphyrin in the binding sites, PPM(CD) and PP(CD), showed fluorescence quenching according to the binding of (-)-cinchonidine, and the quenching was significant in the low-concentration range, suggesting that the high-affinity binding sites contain the porphyrin residue. The correlation of the relative fluorescence intensity against log of (-)-cinchonidine concentrations showed a linear relationship. These results revealed that the MIP having highly specific binding sites was assembled by the two functional monomers, vinyl-substituted zinc(II) porphyrin and methacrylic acid, and they cooperatively worked to yield the specific binding. In addition, the zinc(II) porphyrin-based MIPs appeared to act as fluorescence sensor selectively responded by binding events of the template molecule.
Takeuchi
T
T
Laboratory of Synthetic Biochemistry, Faculty of Information Sciences, Hiroshima City University, Hiroshima, Japan. takeuchi@im.hiroshima-cu.ac.jp
Mukawa
T
T
Matsui
J
J
Higashi
M
M
Shimizu
K D
KD
D001665:Binding Sites; D002930:Cinchona Alkaloids / Q000378:metabolism; D008665:Metalloporphyrins / Q000737:chemistry* / Q000378:metabolism; D008689:Methacrylates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D002930:Cinchona Alkaloids; D008665:Metalloporphyrins; D008689:Methacrylates; D011108:Polymers; C008384:methacrylic acid; C041622:cinchonidine