New Strategy for the Cleaning of Paper Artworks: A Smart Combination of Gels and Biosensors

Abstract

In this work an outlook on the design and application, in the cultural heritage field, of new tools for diagnostic and cleaning use, based on biocompatible hydrogels and electrochemical sensors, is reported. The use of hydrogels is intriguing because it does not require liquid treatment that could induce damage on artworks, while electrochemical biosensors not only are easy to prepare, but also can be selective for a specific compound and therefore are suitable for monitoring the cleaning process. In the field of restoration of paper artworks, more efforts have to be done in order to know how to perform the best way for an effective restoration. Rigid Gellan gel, made up of Gellan gum and calcium acetate, was proposed as a paper cleaning treatment, and selective biosensors for substances to be removed from this gel have been obtained by choosing the appropriate enzymes to be immobilized. Using this approach, it is possible to know when the cleanup process will be completed, avoiding lengthy and sometimes unnecessary cleaning material applications.

Toward a Reversible Consolidation of Paper Materials Using Cellulose Nanocrystals

“…The procedure of the working electrode surface modification protocol was reported in a previous work. 34 The bioreactor for nanocellulose analysis was a hand-made cylindrical reactor in Plexiglass in which an enzymatic ABC Immunodyne membrane (Pall Corporation, Ireland) was inserted into the flow system. The membrane had an immobilization surface of 300 cm 2 , with a thickness of 150 μm.…”

“…The interesting aspect and true novelty of the restoration of paper performed by the application of a protecting coating with CNCs is the reversibility of the treatment, a capability that we are able to demonstrate. To ensure this reversibility, we used a cleaning method, based on the application of a Gellan hydrogel on the paper surface; 3,4,33,34,37,38,40 the other surface of the gel is coupled with a flow sampling plate, in line with an electrochemical system designed ad hoc for sensing the amount of cellulose eventually removed from the paper surface. 3,34,37,38 Gellan hydrogel is a Gellan gum-based hydrogel, widely used for the cleaning of paper artworks.…”

“…To ensure this reversibility, we used a cleaning method, based on the application of a Gellan hydrogel on the paper surface; 3,4,33,34,37,38,40 the other surface of the gel is coupled with a flow sampling plate, in line with an electrochemical system designed ad hoc for sensing the amount of cellulose eventually removed from the paper surface. 3,34,37,38 Gellan hydrogel is a Gellan gum-based hydrogel, widely used for the cleaning of paper artworks. 3,4,33,34,37,38,40 During the cleaning process, it can be applied on paper as a rigid one body and allowed to act as a water reservoir, releasing small amounts of water in a controlled way.…”

“…3,34,37,38 Gellan hydrogel is a Gellan gum-based hydrogel, widely used for the cleaning of paper artworks. 3,4,33,34,37,38,40 During the cleaning process, it can be applied on paper as a rigid one body and allowed to act as a water reservoir, releasing small amounts of water in a controlled way. Water acts as a cleaning agent, removing patinas, dust, as well as byproducts of cellulose hydrolysis and oxidation from paper.…”

Confined Aqueous Media for the Cleaning of Cultural Heritage: Innovative Gels and Amphiphile-Based Nanofluids

“…Ca 2+ added as calcium acetate solution) contributes to stabilization of the structure, enhancing gel strength and elasticity (Mao et al 2001). The ability of gellan gum hydrogels to perform a safer cleaning action on paper artifacts was compared to those of a traditional water bath by Micheli et al (2014). Mazzuca et al (2014) used gellan gum gels in association with enzymes for the removal of starch paste from paper and assessed the absence of residues with chromatographic techniques.…”