This manuscript describes a new type of nanomaterial. namely superparamagnetic Au@Co nanochains with optical extinctions in the near infrared (NIR). The Au@Co nanochains were synthesized via a one-pot galvanic replacement route involving a redox-transmetalation process in aqueous medium. where Au salt was reduced to form Au shells on Co seed templates. https://lecoureures.shop/product-category/ski-de-fond-accessoires-sac-a-ski/