The present invention relates to 3D printable composition comprising a cross-linkable component, a non-cross-linkable polymer, and analyte sensor particles, and to a method of fabricating a scaffold for living cells, a scaffold for a living cell, and a kit of parts comprising components for performing the method to obtain the scaffold. The scaffold is useful for prolonged culture of living cells and allows monitoring a metabolite throughout the culture with high spatial resolution of the metabolite in the scaffold.