Label-free detection of porcine gelatin: A reliable immunosensor based on multi-walled carbon nanotubes and gold nano-urchins

•Gelatin biosensor based on MWCNTs/CS/AuNUs nanocomposite was fabricated by drop-casting method.•Physical adsorption method was employed to immobilize anti-PSG on the surface of GCE.•The fabricated immunosensor demonstrated satisfactory reproducibility, and anti-interference ability.•Fabricated immunosensor has great commercial implications in halal food industries.