Laccase-biosilica nanostructures - A miniaturized automatic approach

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Marieta L C Passos (Author) Other; Jose L F C Lima (Author) FFUP; Lucia L M F S Saraiva (Author) FFUP

Journal

Title: Canadian Journal of Chemistry

Vol. 91

Pages: 113-119

ISSN: 0008-4042

Publisher: NRC Research Press

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 2 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-006-EET

DOI: 10.1139/cjc-2012-0193

Abstract (EN): In the present work, an automatic generic tool for performing different syntheses of biosilica nanoparticles and the encapsulation of enzymes at the same time is described. Sequential injection analysis (SIA) allowed automation, since it enables the precise and exact control of fluidic manipulations as well as reaction conditions essential for achieving repeatable and reproducible hydrolysis, nucleation, and particle growth. An effective computer control of all the analytical parameters during run time ensured the testing of different templates, silicic acid precursors, and reaction conditions (flow rates, flow reversal, mixing, order of reagents added, pH, etc.) without physical reconfiguration of the flow setup. The effect of tetramethyl orthosilicate, sodium silicate, polyethylenimine, and protamine was evaluated not only for the morphology and size of obtained nanoparticles, but also for the stability and consequently the activity of laccase, the enzyme selected for this demonstration. This activity was evaluated using the spectrophotometric measurement (at 415 nm) of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radical, which results from the action of the encapsulated enzyme. The results obtained showed advantages, namely, reproducibility between all the samples used when compared with the small-scale batch-based process, and the absence of clogging due to the operational characteristics of the SIA technique. Besides the benign reaction conditions, such as ambient temperatures, physiological pH range, and aqueous solvents, this automatic procedure was shown to be a rapid, simple, and more sensitive alternative method for the enzyme immobilization that results in the physical entrapment of enzymes within silica nanospheres as they are formed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7