A Portable Fiber Optic Real-time Smartphone-based Visible Spectrometer

A portable and cost-effective smartphone spectrometer was designed and tested for colorimetric analysis. The ambient light sensor of smartphone was applied as a detector, and an external light-emitting diode (LED) was used as a light source. An optical fiber is used to connect the cuvette and the mobile phone. Additionally, an Android smartphone application was designed for automatically quantifying the spectral parameters, such as absorbance and transmittance based on transmitted light intensity detected by the smartphone ambient light sensor. Determination data can be quickly verified on the spot and be displayed immediately on the phone screen. The device was evaluated by determining malachite green samples and compared with a commercial spectrophotometer. Results showed that this device can perform well with a simple structure and low-cost. The absorbance data read by this device were as high as that of commercial device. A linear regression (R2=0.999) was achieved with a linear range(0~75mg/L) in the experiment of quantifying malachite green, with RSDs ranged from 0.12% to 0.48 %. Results demonstrated that our device showed good accuracy and stability in fast speed. With the advantages of cost-effective, user friendly and portability, this smartphone spectrometer holds great application potential in many application fields.