Miniaturized solid-state ion sensors based on field-effect transistors on silicon can take advantage of the capabilities of microelectronics and microsystems technology for the integration of combined functionalities. Optimized solidstate chemical sensors usually require specific materials and fabrication processes. However, if standard fabrication processes can be used, integrated chemical sensor systems can be developed in a shorter time and in a cost effective way. We show that, for applications in which a long operating time is not required, such as in disposable biomedical sensors, good integrated sensor systems can be fabricated with standard materials and processes. Specific examples are presented, such as multisensor systems, sensors with integrated signal-processing circuits and sensors with particle manipulation electrodes.