In this paper, nanotechnology, Nanosensor, Nanodevices, bionics of nanotechnology are discussed. The significance of the topic includes its contribution to biology and medicine as well as to engineering and technology. Cell may be the best object to be researched. Cell membrane,may be the key of such a study. By mean of simulating the structure and function of a cell's membrane, a molecular systematic model of nanorobot and a molecular network model of nanofactory are suggested. Methodologies for realizing such models are presented. Among them, nanofabrication biotechnology, chemical method and nanointegration are illustrated. Nanofabrication in a broad sense will be preferable to others. At last, a diagram showing the perspectives of the new technologies including measuring and control of psychological state, establishing platform for monitoring a single cell, constructing nanorobot and nanofactory etc. was depicted.

In this research, a near-IR fluorescent labeled nucleic acid conjugate for the nucleic acid detection was synthesized, and characterized preliminarily for the detection of the nucleic acid. Th conjugate combines the molecular recognition properties of the oligonucleotides with the near-IR fluorescence label PR646. Both single- and dual- labeled conjugates were studied for their hybridization with the complementary nucleic acid. The dual labeled conjugate has indicated that the self-quenching effect exists in ssDNA form while the fluorescence increases greatly after hybridization with the complementary nucleic acids. The time-resolved fluorescence was also studied.

Calcium ion is a very important messenger not only between cell and cell, but also in meridian main and collateral channels. A new neutral carrier PVC membrane based needle-type potential sensor was prepared, which shows a good selectivity for Ca2+. Responses characteristics, pH, response time of sensor, other metal ions such as Mg2+, Na+, and K+ in measuring calcium ion were investigated. The resulting sensor has a linear range from 1.0 x 10(-6) to 9.1 x 10(-3) mol/L. The sensor will be used in the detection of Ca2+ in vivo in muscular tissues of the mice.

A new instrument for the determination of low concentrations of nitrite is presented Nitrite reacts with I- in acidic medium to form nitric oxide that is subsequently removed from reaction solution by scrubbing with argon gas, then nitric oxide is detected by Luminol/H2O2 Chemiluminescence detection. The detection limit of nitrite is 10 pmol (1 X 10(-7) mol/L for 100 uL samples) for S/N=3. The calibration graph is linear up to 1000 pmol. The coefficient of variation for 500 pmol nitrite in samples is 4.87%. Analysis time for single test is 250 S The result are in good agreement with a spectrophotometric method The new method offers the advantages of low cost, short analysis time, small samples(10-100uL), resistance to interfering ions and has been applied to the analysis of a variety of biological samples.

A new kind of silane coupling agent, N-(β-aminoethyl)-γ-aminopropyl triethoxysilane, was used for DNA direct attachment on the surfaces of glass supports, then the immobilized DNA was hybridized with horseradish peroxidase (HRP)-labeled probe, and detected by using enhanced chemiluminescent method. In comparison with 7-aminopropyl triethoxysilane, the detection limits (S/N) of DNA were 10 pg and 75 pg respectively. Several experimental conditions of DNA attaching to glass supports were investigated, and the system of hybridization of nucleic acid on the surfaces of glass supports was developed.

A novel fiber-optic DNA biosensor based on chemiluminescence is proposed. DNA probes were covalently immobilized onto the distal end of the optical fiber bundle. Hybridization of HRP (horseradish peroxidase)-labeled complementary nucleotides to the immobilized probes was detected by enhanced chemiluminescence. The detection limit (S/N=3) is 0.1 ppm. The approach is shown to be specific, sensitive and capable of diagnostic applications.

This chapter elaborates neuron-mimetic molecular sensor. Neuron is the basic biological unit for signal transducing and processing. A molecular sensing system that mimics both the neuron receptor and neuron membrane, was designed, synthesized and assembled. It consists of a crown ether group and a steroid group. The system integrated the functions of molecular recognition, optical signal transducing and LB membrane assembly. It is transferred to the tip of optical fiber mimicking the neuron fiber to construct a neuron-mimetic molecular sensor. The chemical signals turn into the optical signals — the reflectant spectrum differences, then output through the optical fiber is produced. The neuron-mimetic molecular sensor can be used in the determination of amino acids and detection of their chirality. For phenylalanine, the detection limit is 10−5 mol/L The novel sensor is especially useful for bioelectronical and molecular electronical studies and may offer a potential tool for molecular medicine.

This chapter discusses development of a needle-type biosensor for the traditional Chinese medical acupuncture therapy and the assay of dopamine. The traditional Chinese medical acupuncture therapy is widely spread over the world now. The Meridian theory, as the theoretical basis for the traditional Chinese medicine, has directed the manipulation for a long time. To monitor the molecular event occurring in meridian and acupoint, a novel biosensor which is a combination of the traditional Chinese medical sensing needle and tissue-based carbon paste microelectrode has been developed. The biosensor, which is both an actuator and a sensor, can be employed to the acupuncture therapy as well as detection of neurotransmitter-dopamine (DA). The construction of biosensor a stainless steel hollow sensing needle with inner wall insulated, and a small hole on its lower part is filled with spinach tissue-based carbon paste which is electrically connected by inserting a copper wire. The detection limit reaches 10−7 mol/L and the life time one month. In vitro characterization experiments have shown the sensor's performance to be acceptable. The biosensor is used in the initial study of neurotransmitter DA in acupoint.