%I Nature Research %A I.G. Subramani %A V. Perumal %A S.C.B. Gopinath %A N.M. Mohamed %A M. Ovinis %A L.L. Sze %V 11 %T 1,1'-Carbonyldiimidazole-copper nanoflower enhanced collapsible laser scribed graphene engraved microgap capacitive aptasensor for the detection of milk allergen %R 10.1038/s41598-021-00057-4 %N 1 %D 2021 %J Scientific Reports %L scholars14189 %O cited By 6 %K allergen; aptamer; copper; graphite; imidazole derivative; lactoglobulin; N,N-carbonyldiimidazole; nanomaterial, animal; chemistry; electrochemical analysis; food analysis; genetic procedures; limit of detection; milk; procedures, Allergens; Animals; Aptamers, Nucleotide; Biosensing Techniques; Copper; Electrochemical Techniques; Food Analysis; Graphite; Imidazoles; Lactoglobulins; Limit of Detection; Milk; Nanostructures %X The bovine milk allergenic protein, �β-lactoglobulin� is one of the leading causes of milk allergic reaction. In this research, a novel label-free non-faradaic capacitive aptasensor was designed to detect β-lactoglobulin using a Laser Scribed Graphene (LSG) electrode. The graphene was directly engraved into a microgapped (~ 95 µm) capacitor-electrode pattern on a flexible polyimide (PI) film via a simple one-step CO2 laser irradiation. The novel hybrid nanoflower (NF) was synthesized using 1,1�-carbonyldiimidazole (CDI) as the organic molecule and copper (Cu) as the inorganic molecule via one-pot biomineralization by tuning the reaction time and concentration. NF was fixed on the pre-modified PI film at the triangular junction of the LSG microgap specifically for bio-capturing β-lactoglobulin. The fine-tuned CDI-Cu NF revealed the flower-like structures was viewed through field emission scanning electron microscopy. Fourier-transform infrared spectroscopy showed the interactions with PI film, CDI-Cu NF, oligoaptamer and β-lactoglobulin. The non-faradaic sensing of milk allergen β-lactoglobulin corresponds to a higher loading of oligoaptamer on 3D-structured CDI-Cu NF, with a linear range detection from 1 ag/ml to 100 fg/ml and attomolar (1 ag/ml) detection limit (S/N = 3:1). This novel CDI-Cu NF/LSG microgap aptasensor has a great potential for the detection of milk allergen with high-specificity and sensitivity. © 2021, The Author(s).