集成生物微环境测量CMOS传感芯片研究  

Research on integrated CMOS biosensor chip for bio-microenvironment measurement

作　　者：孙颖[1] 朱大中[1] 

机构地区：[1]浙江大学微电子与光电子研究所,杭州310027

出　　处：《仪器仪表学报》2010年第2期352-357,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(60576050)资助项目

摘　　要：基于标准0.6μm CMOS工艺设计实现了单片集成可用于细胞外微环境溶液pH值和温度同时检测的混合信号生物传感芯片。利用多层浮栅结构场效应管作为pH值传感单元,在恒流恒压电路控制下得到与pH值成反比的电压输出。pH敏感器件与参比器件的差模输出方式有效减小了电路和溶液的噪声。pH值在1～13范围内,传感器平均灵敏度为35.5mV/pH,线性度优于3.2%。芯片上还集成了与绝对温度成正比的温度传感器,可实时检测生物微环境溶液的温度变化,在25～100℃范围内,输出线性度优于1.7%,平均灵敏度为8.8mV/℃。此外,构建了传感芯片的原型应用电路,对传感器的输出电压进行软件修正后以温度和pH值形式进行显示,以实现两个参数的实时监测。在25～70℃温度范围内,温度测量偏差在-0.6～+1.1℃以内,pH值的测量偏差≤±0.3pH。该芯片具有一定的可重用性,既可用来研究温度变化对细胞微环境溶液pH值的影响,又可作为IP核兼容集成于相同工艺的其他传感器电路中。A monolithic mixed signal biosensor circuit for extracellular microenvironment solution pH value and temperature measurement is designed based on standard 0.6μm CMOS technology in this paper.A field effect transistor with multi-level floating gate structure is used for the pH sensor unit.The output voltage of the circuit is inversely proportional to the pH value under the control of a constant source-drain voltage and current module.The differential output mode of the pH sensitive device and pH reference device reduces the noise from the solution and circuits.Test results show that the pH sensor has an average sensitivity of 35.5 mV/pH from pH1 to pH13 and its linearity is better than 3.2%.A PTAT（Proportional To Absolute Temperature） temperature sensor for detecting the temperature of bio-microenvironment solution in real-time is also integrated in this biosensor IC,and its average sensitivity is 8.8 mV /℃ and its linearity is better than 1.77% from 25 ℃ to 100 ℃.A real-time data processing and display prototype system is also realized to display the temperature and pH value simultaneously after software correction.The temperature test error of the system is-0.6～＋1.1℃ in the range from 25 ℃ to 70 ℃ and its pH test error is less than ±0.3 pH.This biosensor IC can be used to investigate the influence of temperature variation on pH value of cell microenvironment solution.It can also be used as an IP core and reused in all other sensor circuits with the same technology.

关 键 词：生物传感芯片 PH传感器 多层浮栅场效应管(MFGFET) 温度传感器 监测系统 

分 类 号：TN432[电子电信—微电子学与固体电子学]