Molecularly Imprinted Hydrogels from Colloidal Crystals for Detection of Progesterone

NATALIA CASÍS; CARLOS BUSATTO; MARIA MARTA FIDALGO DE CORTALEZZI; SERGE RAVAINE; DIANA ESTENOZ

Cancún

Congreso; XXII International Materials Research Congress IMRC 2013; 2013

The increased global concern about ?gemerging contaminants?h in wastewater derived from pharmaceutical family such as endocrine disruptor stimulates the development of new selective analytical methods of detection [1-2]. Steroid hormones are released into surface waters in large amounts generating adverse biological effects on health. Exposure to environmental estrogens has been shown to decrease sperm counts, increase rates of testicular, prostate, and breast cancers, and produces reproductive disorders in human males [3]. Conventionally methods to detect compound involve not only expensive instruments, but also a large number of separate analytical procedures, resulting in a complex, time-consuming, and laborious screening procedures. In this work, the synthesis of a new nanoporous material based on molecularly imprinted polymers (MIPs) is studied. The novel procedure combines the non-covalent imprinting method with the colloidal crystal template technique. The colloidal crystals made of silica particles were obtained by Langmuir-Blodgett and self-assembly techniques and exhibited a considerable control of the film thickness. Hydrogels films were prepared by polymerizing acrylic acid and ethylene glycol dimethacrylate in the presence of 2,2?L-azobisisobutyronitrile as initiator and progesterone as targeted molecule. The polymerization took place in the interspaces of the colloidal crystal using a UV lamp at ?É = 365 nm. After the reaction, silica particles and progesterone were removed to produce a 3D ordered structure. The nanocavities derived from progesterone, were distributed within the walls of the internal structure of the films. The equilibrium swelling properties of the MIPs were studied as a function of crosslinking degree and pH. The pore morphology of the film was analyzed by SEM. The MIP characterizations were accomplished by several techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and evaluation of their sensing and selective properties.