The molecular sensing of protein and DNA molecules with nanopore sensor arrays necessitates high-speed readout interfaces. This leads to high output data rates, while only a very small portion of the recorded data contains useful translocation data. The high data rate creates a bottleneck for the design of high-density arrays of nanopores. This article addresses the issue by proposing an event-based recording approach. In this approach, the transmembrane current is monitored in all nanopores, and it is recorded only from the nanopores, in which a translocation event is detected. A prototype is presented, in which the proposed translocation event recording approach is implemented for a 16-nanopore array along with a resistive feedback transimpedance amplifier (TIA) and an successive approximation reduction (SAR) analog-to-digital converter (ADC). The TIA achieves 0.646-nArms noise performance and a 0.92-MHz bandwidth with the electrical model of a typical solid-state nanopore. The SAR ADC samples the TIA output at 2 MS/s and achieves 9.1 ENOB. The experiments to test the event detection approach with solid-state nanopores and barcoded DNA are also presented with the results.