1 Introduction Nanomaterials (NMs), especially inorganic metal NMs, such as single, bimetallic, and trimetallic NMs are widely applied in chemistry, energy, electronics, and biomedical fields. Traditional physical/chemical NMs synthesis methods require harsh conditions and high energy consumption. Whereas microorganisms form NMs by depositing and assembling ions/molecules, which is an eco-friendly, mild, and sustainable strategy [1-5].