Evaporation of sessile droplet containing suspension of cellulose nanocrystals (CNC) results on birefrin-gent coffee ring pattern (CR), due to the concentration increase and self-assembly of CNC carried by theflow at the edge of evaporating droplet. In this work, we studied the apparition of Maltese cross pattern,(MC) after addition of an hydrosoluble biopolymer belonging to the hemicellulose family, i.e. arabinoxy-lan (AX). To investigate the mechanisms that control MC pattern apparition, distribution of the two com-ponents inside the dried droplet was investigated using FTIR. CNC and AX were found to behomogenously deposited and CNC self-assembly induces nanoparticles orientation in the CR deposit.We demonstrate that the increase of concentration during drying induces gelation of CNC/AX mixtureleading to MC pattern apparition. We take advantage of the apparition of MC pattern to develop a novelcatalytic activity detection assay based on the variation of viscosity. Indeed, addition ofEndo-1,4-b-Xylanase (Xyl) addition to a suspension containing CNC/AX complex leads to hydrolysis of AX thatdecrease in droplet viscosity leading to MC disappearance. The enzymatic detection assay is thus simple,easy to handle, fast, sensitive and do not require complex analytical devices