Research On Fluorescence Detection System For Neonatal Phenylketonuria Screening

Phenylketonuria(PKU) is a genetic disease as a result of chromosome abnormality, which can cause the metabolization disorder of phenylalanine. If Left untreated, the disorder would damage the neural system greatly and cause nonreversible mental retardation as a result of the accumulation of phenylalanine . Therefore, it is of great importantance to diagnose and treate PKU as early as posible for nowborns. Unfortunately, there is no domestic instrument specially designed for PKU screening at the present time. The aim of this project is to develop a fluorescence detection system for neonatal phenylketonuria screening.Main points discussed in this article are listed as follows:1.Deduced the reaction mechanism of phenylalanine and ninhydrin, based on which we designed a designed a new reagent which used in phenylalanine measurement. Found a new method to aggrandize and stabilize fluorescence and also we devoloped the first demestic reagent box for PKU screening through many clinic experiments.2.Using a high luminance ultraviolet LED for excitation source, a"Y"type fiber which consists of quartz and Glass fiber with different diameter for conduction of light, an autofocus fiber for focalization, and a photo multiplier tube for measurement. Designed a new optical system for neonatal phenylketonuria screening and demonstrate the feasibility of it in theory. Experiments show that this optical system is sensitive, simple, small and light.3.Adopted a double-parallel-rail frame, and used two marching electromotor for driving, four sensor for locating and standard 96-tiny hole board system for scanning, which at the same time has the ability to mix specimens and keep constant temperature.4.Adopted embedded PC frame for the designing of the hard ware circuits of the PKU detecting system which has multiple functions such as the preprocessing of electrical and optical signal, A/D converting, scanning driving, tiny-hole board shaking and constant temperature keeping, etc. Designed a data processing software using VC++ based on WINDOWS. The system has the advantages in the following aspects: highly intellectualized, easy maintenance and upgrading, strong statistical and analyzing capability, direct access to the internet, etc.Clinic experiments indicate that the system is stable, easily operated, accurate, and with low cost, which meets the demand of clinic application. This system provides a new method for mass PKU detecting. The project is supported by Tianjin Social Development fund and has been accepted by Tianjin Scientific Committee.