Immobilization of alpha-amylase on functionalized magnetic iron oxide nanoparticles: evaluation of activity under alternating magnetic field

• Grant number: 25/13994-1
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2025
• End date: October 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Rodrigo Fernando Costa Marques
• Grantee: Rodrigo Fernando Costa Marques
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 23/01953-3 - Materials applied to transformation of biomass in green diesel: from laboratory to pilot, AP.BIOEN.TEM

Abstract

The growing demand for sustainable fuels has driven research into alternative routes for converting biomass into clean energy sources. In this context, advanced biofuels such as HVO (Hydrotreated Vegetable Oil) and SAF (Sustainable Aviation Fuel) emerge as promising alternatives to partially or fully replace fossil fuels. Both can be derived from intermediates generated by biochemical processes that use fermentable sugars as precursors. The hydrolysis of starch by enzymes like alfa-amylase is a strategic step in converting starchy biomass into reducing sugars, which are then fermented into short-chain alcohols-key feedstocks for HVO or SAF production. However, the limited thermal and pH stability of alfa-amylase restricts its industrial use in continuous processes.This project proposes the development of a catalytic system based on the immobilization of alfa-amylase onto superparamagnetic iron oxide nanoparticles, previously functionalized with different silane agents: APTES (amine), MPTMS (thiol), and GPTMS (epoxy). Iron oxide was selected due to its stability, biocompatibility, magnetic separability, and the research group's extensive prior experience in nanoparticle synthesis and surface functionalization. Alternating magnetic field (AMF) will be explored as a strategy for remote enzyme activation, through Néel and Brownian relaxation mechanisms that promote localized microheating and agitation, enhancing catalytic efficiency without significantly increasing bulk temperature.The project includes: chemical coprecipitation of iron oxide nanoparticles; surface functionalization with selected silanes; covalent enzyme immobilization via glutaraldehyde crosslinking; characterization using FTIR, XRD, SEM, TGA, DLS and zeta potential; and enzymatic activity evaluation under AMF and control conditions. Enzymatic response will be compared across different functional groups, aiming to optimize performance, stability, and reusability. The most promising system will undergo reuse and thermal stability tests to simulate real process conditions.The proposed study is expected to contribute to the advancement of innovative catalytic platforms for biorefinery applications and renewable fuel production, utilizing starchy residues while enabling cleaner and more efficient biochemical biomass conversion routes. (AU)