Steady-state and frequency-domain lifetime measurements of an activated molecular imprinted polymer imprinted to dipicolinic acid.
We recently demonstrated the synthesis and fluorescence activity associated with an optical detector incorporating a molecular imprinted polymer (MIP). Steady-state and time-resolved (lifetime) fluorescence measurements were used to characterize the binding activity associated with MIP microparticles imprinted to dipicolinic acid (DPA). DPA is a unique biomarker associated with the sporulation phase of endospore-forming bacteria. Vinylic monomers were polymerized in a dimethylformamide solution containing DPA as a template. The resulting MIP was then pulverized and sorted into small microscale particles. Tests were conducted on replicate samples of biologically active cultures representing both vegetative stationary phase and sporulation phase of Bacillus subtilis in standard media. Samplers were adapted incorporating the MIP particles within a dialyzer cartridge (500 MW). The permeability of the dialyzer membrane permitted diffusion of lighter molecular weight constituents from microbial media effluents to enter the dialyzer chamber and come in contact with the MIP. Results showed dramatic (10-fold over background) steady-state fluorescence changes (as a function of excitation, emission and intensity) for samples associated with high endospore biomass (DPA), and a frequency-domain lifetime of 5.3 ns for the MIP-DPA complex.
Anderson
John
J
US Army ERDC-TEC, Fluorescence Spectroscopy Lab, 7701 Telegraph Road, Alexandria, Virginia 23415, USA. john.anderson@erdc.usace.army.mil
Nelson
Jean
J
Reynolds
Charles
C
Ringelberg
Dave
D
Tepper
Gary
G
Pestov
Dmitry
D
D001412:Bacillus subtilis / Q000737:chemistry; D015415:Biomarkers / Q000032:analysis / Q000737:chemistry; D005453:Fluorescence; D010848:Picolinic Acids / Q000032:analysis / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
D015415:Biomarkers; D010848:Picolinic Acids; D011108:Polymers; C004860:dipicolinic acid