A fully integrated CMOS bio-chip is designed in a SMIC 0.18μm CMOS mixed signal process and successfully integrated with a novel bio-nano-system. The proposed circuit integrates an array of 4 × 4 （16 pixels） of 19μm × 19μm electrodes,a counter electrode, a current mode preamplifier circuit （CMPA） ,a digital decoding circuit,and control logics on a single chip, It provides a - 1.6- 1.6V range of assembly voltage,Sbit potential resolution, and a current gain of 39.8dB with supply voltage of 1.8V. The offset and noise are smaller than 5.9nA and 25.3pArms,respectively. Experimental resuits from on-chip selective assembly of 30nm poly （ethylene glycol） （PEG） coated magnetic nano-particles （MNPs） targeted at biosensor applications are included and discussed to verify the feasibility of the proposed circuits.
