Abstract

An inexpensive detector for proteins is described. The detection technique was based on two-photon excitation intrinsic protein fluorescence using a visible 532 nm diode-pumped nano laser as the excitation source. Proteins that exhibit intrinsic fluorescence must contain at least one tryptophan, tyrosine, or phenylalanine residue in their amino acid sequences. The detector was characterized and was found to have a detection limit of 4 micro-molar for tryptophan, 22 micro-molar for tyrosine and 500 micro-molar for phenylalanine. Bovine serum albumin, a serum protein with 3 tryptophan residues in its amino acid sequence was also used to characterize the detector. It was found that the detection limit for this protein was 0.9 micro-molar. The detector volume was determined based on a photon counting histogram - a technique in fluorescence fluctuation spectroscopy. From the results of this analysis, the excitation volume was found to be 2.9 fL. With such an excitation volume, the detection limits were either within or below the atto-mole range.

Degree

MS

College and Department

Physical and Mathematical Sciences; Chemistry and Biochemistry

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2004-04-21

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd416

Keywords

protein detection, two-photon excitation fluorescence of proteins, intrinsic protein fluorescence, tryptophan fluorescence, tyrosine fluorescence, excitation volume, chemosensors, cadmium detection

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