The latest non-invasive biomedical electronic sensors are capable of providing continuous reliable information, for instance oxygenation level of blood, level of glucose etc. These biomedical sensors are in general based on the electro-chemical or spectral properties of the substances. The absorption of blood in infrared and visible range is prominently determined by haemoglobin. The coefficient of absorption for blood is different at different wavelengths. This optical absorption characteristic of the blood yields the vital information on the composition of the blood. Haemoglobin is primarily used to measure the status of anaemia, in developing countries like India and other African countries numerous people with greater health needs don’t have access to proper diagnostic facilities. Therefore, an introduction of portable, low cost and non-invasive Haemoglobin detector will give a vast opportunity for screening the population suffering with anaemia. The present article purposes a non-invasive method of haemoglobin detection comprising of an organic photovoltaic cell and three LED’s sources i.e., blue, green and red which are used with their respective radiation spectral range of 450–495 nm, 495–570 nm and 620–750 nm to illuminate an area of the skin on finger, this transmitted light after interacting with tissues is detected by an arrangement of Coumarin 30 : C60/NN′-QA/ZnPc active layer based organic solar cell. Thus, the approach provide in this article presents a simple, biocompatible and flexible means for assessing blood haemoglobin level by utilizing an multi spectral optical processing method. The method developed herein could further be integrated to wearable electronic devices.