A series of Silicon on Insulator (SOI) photonic wire based evanescent field multi-channelled biosensor array "Lab on a Chip" device configurations and designs are presented, which are based on the author's biosensor patent granted in the UK. This work employs the most advanced chip design, fabrication and characterisation technologies developed from the telecom applications. The chip design capitalises on the most sensitive detection method, i.e. the evanescence field and interferometry technology, and implements the multi-mode interferometer (MMI) technology to integrate the multi-channelled biosensor arrays onto a single chip. This design enables the label-free, time domain real time parallel detection and identification of various analytes and molecular interactions in one or more test samples at extremely low concentrations, with extraordinarily high accuracy and sensitivity of detection simultaneously and instantaneously. For example, the limit of detection of low concentrations of molecules at or even below 1×10 -12 M can be achieved. This corresponds to an effective refractive index resolution at a magnitude of 10 -8 or better. The devices are robust, all-optical, highly scalable, energy efficient dynamic sensing devices. Individual sensor can be addressed separately if wish, and with built-in internal reference channels integrated on chip. Sensing and reference channels can be grouped in an array to allow maximum flexibility in measuring individual analytes in a sample or a number of samples simultaneously and instantaneously. This research and development work could potentially open the door to the next generation of low-cost mass production evanescent field multi-channelled biosensor array "Lab on a Chip" instrumentation development for various application fields, and provide a novel way forward towards revolutionising modern analytical technology.