nh ngha S ra i v pht trin ca cm bin sinh hc Cu to chung ca cm bin sinh hc Phn loi tc nhn cn pht hin ng dng ca cm bin sinh hc

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Theo IUPAC (International Union of Pure and Applied Chemistry) th: Cm bin sinh hc (biosensor) l mt thit b tch hp c kh nng cung cp thng tin phn tch nh lng hoc bn nh lng c trng, bao gm phn t nhn bit sinh hc (bioreceptor) kt hp trc tip vi mt phn t chuyn i Cm bin sinh hc l thit b s dng cc tc nhn sinh hc nh enzym, cc khng th, ... pht hin, o c hoc phn tch ho cht . Do vy cu to ca cm bin sinh hc bao gm 3 thnh phn c bn: thnh phn ho hc, thnh phn sinh hc v thnh phn vt l.

Gio s Leyland D.Clark c bit nh l ngi i tin phong trong lnh vc cm bin sinh hc. Nm 1956 ng cng b bi bo u tin v in cc oxy ho. Nhng nm tip theo ng tip tc thc hin rt nhiu th nghim nhm c gng m rng kh nng hot ng ca cm bin nh pht hin c thm nhiu tc nhn, nng cao chnh xc ca cm bin. Vo nm 1962, ti hi ngh New York Academy of Science, ng thuyt trnh mt bi v cm bin sinh hc: To make electrochemical sensors (pH, polarographic, potentiometric or conductometric) more intelligent by adding enzyme transducers as membrane enclosed sandwiches. ng a ra m hnh u tin v cm bin sinh hc.

Cm bin sinh hc theo m hnh ca D.Clark bao gm in cc oxy ha, trn c mng gi enzyme glucose (glucose oxidase). Khi mt glucose trong mi trng phn ng gim th mt cht oxi ha trn b mt in cc cng gim mt cch tng ng. Da trn s thay i , Clark pht hin ra s thay i ca nng glucose trong mi trng cn kim tra.

S ra i biosensorNhng nm tip theo, nhm ca Guilbault v Montalvo ln u tin cng b chi tit v ch to thnh cng cm bin sinh hc da trn in cc cha enzyme o in th, mt cm bin o nng ur da trn in cc c nh enzyme ur (urease) bng mng cht lng chn lc NH4+. Nm 1975 Lubber v Opitz m t mt cm bin si quang (fibre-optic sensor) gn cc cht ch th dng o nng CO2 v O2. Cng vo nm 1975, mt s vi khun cng c s dng nh nhng thnh phn sinh hc trn cc in cc vi sinh o nng cn. Nm 1975 cng ty Yellow Springs Instrument (Ohio) ln u tin bin tng ca Clark thnh hin thc thng qua vic thng mi ha cc cm bin sinh hc. Sn phm u tin l thit b phn tch glucose da trn hydrogen peroxide v cng l ct mc u tin nh du s xut hin ca cc cm bin sinh hc trong i sng.

Vo nm 1982, Shichiri v cc ng nghip bo co v m t v cm bin glucose in vivo, l loi cm bin dng kim u tin cho cc xt nghim di da. Cng vi s pht trin nhanh chng ca khoa hc v cng ngh, c bit l cc ngnh cng ngh vt liu nano v cng ngh thng tin, cm bin sinh hc cng t c nhng tin b vt bc, ha hn a ra nhng vi thit b nhm xc nh nhanh, chnh xc cc loi vi khun, virut gy bnh. Cc thit b ny cng c th d tm hay phn tch lng mu rt nh (c vi nM) vi tin cy cao. Hin nay,cc nh khoa hc ang pht trin mt cm bin sinh hc b xu c th pht hin cc protein ung th v cc siu vi trng tim n. Cm bin sinh hc ny c ch to bng cch dng k thut tng t con quay hi chuyn nh h thng nh v v cc ti kh. N s c ch to thnh mt thit b cm tay gip phn tch nhanh hn v d dng hn cc mu m. N c hy vng c th gip cc bc s chn on v kim sot cc dng ung th thng gp v a ra liu php iu tr thch hp nht.

Cu to chung ca mt cm bin sinh hc bao gm bn b phn chnh: u thu sinh hc: c tc dng bt cp v pht hin s c mt ca cc tc nhn sinh hc cn phn tch Tc nhn c nh: gip gn cc u thu ln trn in cc B phn chuyn i: tn hiu gip chuyn cc bin i sinh hc thnh cc tn hiu c th o c c B phn x l, c tn hiu ra: c tc dng chuyn thnh cc tn hiu in my tnh v cc thit b khc c th x l

u thu sinh hcC hai loi u thu sinh hc chnh l: Cc cm bin sinh hc s dng cc enzyme hoc khng th oligonucleotid.V d : cc cht c ngun gc sinh hc, c thit k thc hin mt chc nng c th trong c th sng. Do vy, chng c s dng pht hin mt cht c th. Ngoi ra cn c nhng u thu sinh hc c th c m t gi nh ngc vi u thu sinh hc t nhin, thng qua cc phng php in ho c th pht hin mt s cht.

u thu sinh hc (Biological Receptor): l nhng u thu phn ng trc tip

vi cc tc nhn cn pht hin v c ngun gc t cc thnh phn sinh hc. Da vo cc tc nhn sinh hc s dng ngi ta chia ra thnh mt s loi u thu nh sau: u thu lm t enzyme: u thu sinh hc lm t enzyme l dng u thu ph bin nht. l cc u thu lm t cc enzyme urease, glucose, ... u thu lm t cc khng th/khng nguyn: Cc u thu dng ny c c im l tnh chn lc rt cao ng thi cc lin kt c to thnh kh mnh. u thu lm t protein: Rt nhiu cm bin c u thu sinh hc lm t cc protein nh cm bin pht hin hocmn, xc nh cc cht kch thch thn kinh, ... Cc u thu ny c c im l c tnh chn lc rt cao. Tuy nhin, chng c nhc im l rt kh cch ly. u thu lm t cc axit nucleic: Cc axit nucleic nh ADN, ARN c th s dng lm u thu sinh hc. Cc cm bin c u thu dng ny thng c s dng pht hin t bin v cc sai lch trong cu trc di truyn. u thu kt hp: Vi cc u thu dng ny, ngi ta s dng ng thi hai hay nhiu cc phn t dng (enzyme, khng th, protein, ...) trn mt . Vic kt hp ny m rng kh nng lm vic ca cc cm bin sinh hc. Mt s cm bin dng ny l cm bin xc nh thuc n TNT, cm bin xc nh vi khun bnh than v cm bin th thai. u thu lm t t bo: Cc u thu sinh hc khng ch c lm t cc phn t, nguyn t m n cn c th c lm t cc t bo. Mt s t bo bin i gen ca vi khun c s dng lm u thu sinh hc. Khi c mt cc phn t cht c, cc t bo ny s pht sng, thng qua chng ta xc nh c s xut hin ca cc phn t cht c

Tc nhn c nh Cc tc nhn c nh l mt phn rt quan trng trong cm bin sinh hc. Cc tc nhn ny c nhim v gn kt cc u thu sinh hc ln trn . Ni mt cch khc y l b phn trung gian c tc dng lin kt cc thnh phn sinh hc (c ngun gc t c th sng) vi thnh phn v c. B phn chuyn i y l b phn quan trng trong cm bin sinh hc. C nhiu dng chuyn i nh chuyn i in ho, chuyn i quang, chuyn i nhit, chuyn i bng tinh th p in hoc chuyn i bng cc h vi c. Chuyn i in ho: bao gm chuyn i da trn in th (potentiometric), dng in (amperometric) v dn (conductometric). Chuyn i quang: l chuyn i hot ng da trn cc hiu ng nh: hp th nh sng nhn thy v tia UV; pht x hunh quang v ln quang; bio luminiscence; chemiluminiscence.. Chuyn i nhit: hot ng da trn hin tng thay i entanpi khi hnh thnh hoc ph v cc lin kt ha hc trong cc phn ng ca enzyme. B chuyn i ny c u im hot ng tt vi tt c cc phn ng. Tuy nhin, dng chuyn i ny c tnh chn lc thp. Chuyn i bng tinh th p in (piezoelectric):hot ng da trn nguyn l: tinh th s thay i tn s dao ng khi lc tc dng ln n thay i. Chuyn i dng ny c u im l nhy cao (c picogam), thi gian phn ng nhanh, kh nng c ng cao, c th s dng o c trong mi trng lng v kh. Chuyn i bng cc h vi c :nguyn l hot ng: chiu mt chm laser n b phn x trn b mt mt thanh dm rt mng, nh sng phn x c thu nhn bi photodetector. Thanh mng ny c ch to sao cho ch vi mt lc tc ng rt nh cng lm cho thanh b un cong i. Nh vy tn hiu phn x thu nhn c trn photodetector s b thay i so vi trng hp khng c lc tc dng ln thanh. Cn c vo s thay i tn hiu phn x ny, ngi ta c th xc nh c lc tc dng ln thanh

TC NHN CN PHT HIN C PHN LOI NH SAU:

Cc vi khun: cc vi khun thng c pht

hin bi cc cm bin sinh hc l vi khun Ecoli, vi khun Candida, vi khun bnh than Cc phn t nh: cc phn t nh m cm bin sinh hc c th pht hin c l CO, CO2, phn t gluco, phn t ru, ure, thuc tr su, amino axit, paracetamol, aspirin, penicilin, TNT, cc tc nhn thn kinh khc, Cc phn t sinh hc c kch thc ln: nhng phn t ny c th l cc phn t ADN, RNA, protein, enzyme, cc hocmon,

NG DNG CA CM BIN SINH HC

ng dng trong lnh vc y t v chm sc sc kho: y l lnh

vc c nhiu ci tin cng nh nhiu ng dng nht. Chng ta c th k ra rt nhiu loi cm bin nh cm bin o nng oxi, lng glucose trong mu, cm bin huyt p, Nhng cm bin gip ngi bnh c th thng xuyn theo di tnh hnh bnh tt ca mnh m khng nht thit phi n cc trung tm y t. Ngy nay, cc cm bin dng ny khng nhng tng tin cy, gim thi gian hi p m cn c ch to theo hng cng ngy cng nh gn, r v d s dng. ng dng trong cng ngh mi trng: l cc cm bin dng mi in t xc nh mt ho cht c hi no hoc xc nh nhim ca mi trng nh cm bin xc nh nng kh c (CO2, H2S), xc nh d lng thuc tr su, xc nh nng ca cc kim loi nng, ...

ng dng trong cc tng tc Ngi My: y cng l mt lnh vc

mi m c nhiu nghin cu, ng dng. C th k ra mt s cm bin dng ny nh cm bin nhn dng ting ni, hnh nh, nhn dng cc c trng sinh hc ca con ngi. y cng l lnh vc ha hn c nhiu nghin cu, ng dng mi. ng dng trong vic iu khin, qun l cc qu trnh trong cng ngh sinh hc: Ngy nay, khi cng ngh sinh hc pht trin, ng thi vi vic cc ch phm sinh hc c sn xut rng ri trn qui m cng nghip, cng nh tham gia ngy cng nhiu vo cc qu trnh sn xut khc th mt nhu cu tt yu ny sinh, l vic theo di, qun l, iu khin cc qu trnh sinh hc nh iu chnh lng glucose trong qu trnh nui vi khun..v.v.... Cc cm bin sinh hc t ra c nhiu u im so vi cc phng php truyn thng nh tnh chn lc cao, p ng nhanh, n gin v chnh xc.

Cm n s theo di ca cc bn ! Nhm trnh by : Ngc Thanh Tm Triu Yn Trinh Phan Th Hoi Nhn Phm Th Anh Hoi