Microelectrode arrays (MEA) are widely used to record extracellular action potential (AP) and local field potential (LFP) in electro-psychological studies. Conventional MEA detectors have low linearity (1%) and limited dynamic range (DR<;;70dB). New immunological applications such as mast cell recoding require higher linearity and wider DR. In this paper, we introduce a new MEA detector architecture with a continuous-time (CT) front-end and a discrete-time (DT) backend to achieve high linearity. We also use chopping and antialiasing RC filter to reduce the noise in the CT front-end and the DT back-end respectively so as to achieve wide DR. The new detector is implemented in a 0.35μm CMOS process. SPICE simulation shows that it achieves 0.07% linearity for 20mV_pp input signal and 0.6μV_rms input-referred noise over 1-200Hz for the LFP signal which results in 81.4dB DR. It can also record the AP signal with 66dB DR. The power consumption is 66.5μW from a 3.3V supply.