Encapsulation of purple sweet potato's anthocyanin in CMC-PVA matrix for development of paper strips as a colorimetric biosensor

Abstract

Bioactive compound from local resources such as anthocyanin has a high potential to develop as a biosensor for nitrite detection. As a biosensor, this compound shows instability to certain environmental conditions. To overcome this, bioactive compound may need to encapsulate. The aim of this work is to encapsulate of anthocyanin in the CMC-PVA matrix to improve its stability as paper strip for sodium nitrite detection. The result of this work shows that anthocyanin encapsulated by CMC/PVA matrix has well formed. Encapsulated anthocyanin has good homogeneity and it was strongly immobilized in the CMC/PVA matrix. Encapsulated anthocyanin is attached to the surface of the paper medium and penetrated into the matrix. The strip is shown changing color from red to yellow as it applied to nitrite. The selectivity of biosensor paper strip system is observed for various other chemicals including heavy metals such as Pb2+, Zn2+, Fe3+, Mg2+, NaCl, boric acid, monosodium glutamate, sodium benzoate, and formalin with a concentration of 10000 ppm, respectively, and the biosensor was selective towards nitrite. This work gives a basic information to development of a practical green sensor in the form of paper strips for nitrite detection with good stability and selectivity.