Volume 3 • Issue 6 • 1000e113 J Pet Environ Biotechnol ISSN: 2157-7463 JPEB, an open access journal Open Access Editorial Lai, J Pet Environ Biotechnol 2012, 3:6 DOI: 10.4172/2157-7463.1000e113 *Corresponding author: Edward P.C. Lai, Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada, E-mail: edward_lai@carleton.ca Received September 24, 2012; Accepted September 24, 2012; Published September 29, 2012 Citation: Lai EPC (2012) Development of Molecularly Imprinted Polymers – from Environmental Sensors to Biotechnology Applications. J Pet Environ Biotechnol 3: e113. doi:10.4172/2157-7463.1000e113 Copyright: © 2012 Lai EPC. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Development of Molecularly Imprinted Polymers – from Environmental Sensors to Biotechnology Applications Edward P.C. Lai* Department of Chemistry, Carleton University, Canada Many researchers have concentrated on the development of new methods for rapid determination of endocrine disrupting chemicals (EDCs) that are widely detected in environmental waters. Exposure to EDCs is associated with an earlier onset of puberty, decreased fecundity or fertility, altered sexual behavior, and increased incidence of abnormalities or cancers of the reproductive tract in humans [1]. Te fndings of a new study suggest that some endocrine disruptors may play a role in the obesity epidemic [2]. Direct determination of EDCs in water remains a challenging problem due to their low concentrations (ng/L to μg/L), which is further complicated by the presence of numerous other compounds (pharmaceuticals, personal care products, detergents and natural organic matter). Such matrix efects are formidable even when sophisticated instrumental techniques are used [3,4]. Considerable eforts have been focused on the synthesis of molecularly imprinted polymer (MIP) particles that specifcally recognized estrogenic compounds. MIPs represent a class of smart materials that have artifcially created receptor cavities to mimic biological antibodies. Researchers can imprint a plastic material to create molecularly sized and shaped cavities with specifc interactions to bind the target analyte [5]. MIPs show outstanding afnity towards the analyte in aqueous solution, with a binding capacity as high as 300 mg/g. Tey can be used as sorbent materials in solid-phase extraction (SPE) for the quantitative enrichment of analytes in environmental water samples prior to determination by an instrumental method. Removal of interfering matrix constituents frequently extends the detection limit and improves the accuracy of trace analysis. Te structural dimension of MIPs can infuence partition kinetics, as both submicro- and nano- particle sizes have demonstrated improvements in analyte recovery. MIPs can be synthesized for several natural and synthetic EDCs such as estrone (E1), 17α-estradiol (α-E2), 17β-estradiol (β-E2), estriol (E3), 17α-ethynylestradiol (EE2) and bisphenol A (BPA), among which β-E2 exhibits the strongest estrogenic potency (EC50 0.015 ± 0.002 nM) [6]. Tey have been applied in diferent kinds of electrochemical sensors [7-11] and optical sensors [12,13]. Currently there is no commercial availability of online sensors that are suitable for monitoring EDCs rapidly and cost-efectively. Neither in-line immunosensor nor chromatography would be ideal as they have high costs and maintenance requirements. EDCs at ultra- trace levels in environmental water can be determined by selective pre-concentration using the molecular recognition property of MIP particles. Afer preconcentration, the extract can be quantitatively analyzed by spectrofuorometry, capillary electrophoresis and liquid chromatography-tandem mass spectrometry [14]. However, eforts will be required to optimize various parameters such as washing solvent, elution solvent and breakthrough volume to reduce non-specifc interactions during the selective preconcentration of EDCs from water samples. A novel sensing scheme based on fuorescence quenching of 17β-estradiol (E2) was recently reported. Fluorescence emission from E2 non-specifcally bound onto the MIP was frst quenched by gold nanoparticles. Next nitrite anions penetrated the porous MIP structure to quench the fuorescence emission from E2 molecules specifcally bound inside imprinted cavities. Te diference between these two emission intensities varied with the initial E2 concentration in water from 0.1 to10 ng/mL [15]. One major advantage of this method is the high selectivity of MIP particles for E2 [16] over dissimilar structures [17]. Rapid screening of E2 in water takes only 10 min. In feld studies, ultra-trace EDCs can be more efciently pre- concentrated by fowing 100-1000 mL of water through an optical cell packed with MIP particles. Flow injection analysis (without coupling to a HPLC system) is possible by automated sequential injections of AuNPs and sodium nitrite to make the fuorescence quenching measurements. A detection limit of 15 ng/L will attest to its suitability for rapid feld analysis. Although MIP particles tend to sufer from biofouling, they are so simple in design and so cost efective in synthesis to be disposable afer a single use. As these optical sensors have operational characteristics similar to a pH sensor in terms of durability, selectivity and concentration range, they will be suitable for autonomous, real- time data acquisition in a closed loop system at low maintenance costs. For EDCs which are not inherently fuorescent, quenching of the fuorescence from an indicator probe would be a feasible modifcation of the above measurement principle. Tese two options potentially will allow a suite of EDC sensors to be developed for benzophenone, dichlorodiphenyldichloroethylene, dienestrol, diethylstilbestrol, di- tert-butyl-benzoquinone, hexachlorobenzene, hexachlorocyclohexane, mestranol, nonylphenol, nonylphenol monoethoxylate carboxylate, oxychlordane phenanthrene, progesterone and triclosan. Te selectivity of a new MIP for 3-nitro-l-tyrosine, an oxidative stress marker associated with neuro-degenerative disorders, was demonstrated in human urine analysis [18]. Another MIP was developed for the SPE of irinotecan from human serum [19]. Te fngerprint analysis concept, which distinctively identifes a pool of peptides composing a protein, was recently developed for the rational preparation of MIPs for protein recognition [20]. From environmental sensors to biotechnology applications, the diversity of areas and complexity of systems are both indicating numerous opportunities in the near future. Journal of Petroleum & Environmental Biotechnology J o u rn a l o f P et r o l e u m & E n v iro n m en ta l Bi o t e c h n o l o g y ISSN: 2157-7463