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Multivariate data analysis in biomedical spectroscopy: cholinesterase activity determination Natalia L. Nechaeva Chemical enzymology department, Faculty.

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Presentation on theme: "Multivariate data analysis in biomedical spectroscopy: cholinesterase activity determination Natalia L. Nechaeva Chemical enzymology department, Faculty."— Presentation transcript:

1 Multivariate data analysis in biomedical spectroscopy: cholinesterase activity determination
Natalia L. Nechaeva Chemical enzymology department, Faculty of chemistry Lomonosov Moscow State University

2 Raman spectroscopy Leonid Mandelstam Grigory Landsberg Chandrasekhara
Venkata Raman Kariamanickam Srinivasa Krishnan Peter Naglič. Raman spectroscopy for medical diagnostics. University of Ljubljana

3 Advanced Raman spectroscopy
Surface-enhanced Raman spectroscopy (SERS) Resonance Raman spectroscopy Angle-resolved Raman spectroscopy Hyper Raman Coherent anti-Stokes Raman spectroscopy (CARS) Tip-enhanced Raman spectroscopy (TERS)

4 SERS beginning M. Fleischmann
Raman spectra of pyridine in solution and at the silver electrode. (B) 0.05 M aqueous pyridine; (F) silver electrode -0.6 V. Fleischmann, M., Hendra, P. J., & McQuillan, a J. (1974). Raman spectra of pyridine adsorbed at a silver electrode. Chemical Physics Letters, 26(2), 163–166. doi: / (74)

5 SERS beginning C. L. Haynes
Raman spectrum of a silver electrode immersed in 0.2 M KCI. Raman spectrum of 50 mM aqueous pyridine and 0.1 M KC1. Raman spectrum of pyridine adsorbed on a silver electrode from a bulk solution of 50 mM pyridine and 0.1 M KCI. Haynes, C. L., Yonzon, C. R., Zhang, X., & Van Duyne, R. P. (2005). Surface-enhanced Raman sensors: Early history and the development of sensors for quantitative biowarfare agent and glucose detection. Journal of Raman Spectroscopy, 36(6-7), 471–484. doi: /jrs.1376

6 New life of old SERS-substrate
Acetylcholinesterase (AChE) Macro Butyrylcholinesterase (BChE) Micro

7 Main steps of experiment
Obtaining blood hemolysate Carrying out the enzymatic reaction Applying reaction mixture to the substrate Getting spectra Statistical data treatment

8 Butyrylthiocholine and thiocholine spectra
A lot of problems… Choline – internal standard

9 Changing during the reaction
0 minutes 10 minutes Cal Val RMSE 2,258 5,873 R^2 0,977 0,858 Slope 0,896 30 minutes At any given time [TCh] + [BTCh] = const Cal Val RMSE 0,188 0,265 R^2 0,908 0,822 Slope 0,914 0,901 Cal Val RMSE 0,206 0,417 R^2 0,912 0,658 Slope 0,895 0,773 Как визуально описать эксперимент с переменным значением концентрации Е От 5 февраля графики БХЭ all без 0,4 и 0,8 Для ТХ+БТХ тоже калибровка с проверкой – пару промежуточных концентраций предсказать

10 Cholinesterase activity in blood
100 AChE BChE = 200 samples Spectrophotometry and Raman spectroscopy RANDOM RANDOM Визуально расширить экспериментальную часть Systematic Systematic The enzyme activity as measured the SERS method and Ellman's method

11 Problems… Week equipment (small, portable, but not precise)low quality of spectra (noisy) Probably, not optimal data pretreatment SERS – unexpected process! Complex matrix A lot of problems… …Non-linearity??

12 Non-linearity!!!

13 Further development and application
Organophosphates monitoring Pesticide intoxication Organophosphates Induced Delayed Neuropathy (OPIDN) Blood esterase assay Subclinical mastitis milk detection Choline and Phenol detection Практич применение моего исследования – добавить драмы Thank you for attention!

14

15 Why Raman? High specificity High accuracy Possibility of enhancement
Label free method Tolerant to water Can be combined with non-optic method Min sample preparation Fast Perspective to non-invasiveness


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