fabrication-and-testing-of-microfluidic-optomechanical-oscillators

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

University of Michigan

Optofluidic lasers are of particular interest for lab-on-a-chip-type devices, with broad spectral tunability, convenient microfluidic integration, and a small footprint. Optofluidic ring resonator (OFRR) lasers are advantageous in terms of size but typically generate nondirectional emission that is of minimal practical use. We introduce two unique geometries for soft-lithography-based OFRR lasers--side-coupled rings and spiral rings--both of which can be produced in polydimethyl siloxane substrates with contact molding. These rings utilize evanescent and direct butt-coupling, respectively, to effectively couple the OFRR laser emission into microfluidic channels. A laser threshold of a few to tens of microJ/mm(2) is achieved.

Demonstration of the coupling of optofluidic ring resonator lasers with liquid waveguides.

We develop a novel nL-sized microdroplet laser based on the capillary optofluidic ring resonator (OFRR). The microdroplet is generated in a microfluidic channel using two immiscible fluids and is subsequently delivered to the capillary OFRR downstream. Despite the presence of the high refractive index (RI) carrier fluid, the lasing emission can still be achieved for the droplet formed by low RI solution. The lasing threshold of 1.54 µJ/mm(2) is achieved, >6 times lower than the state-of-the-art, thanks to the high Q-factor of the OFRR. Furthermore, the lasing emission can be conveniently coupled into an optical fiber. Finally, tuning of the lasing wavelength is achieved via highly efficient fluorescence resonance energy transfer processes by merging two different dye droplets in the microfluidic channel. Versatility combined with improved lasing characteristics makes our OFRR droplet laser an attractive platform for high performance optofluidic lasers and bio/chemical sensing with small sample volumes.

Versatile optofluidic ring resonator lasers based on microdroplets.

&#x6211;&#x4EEC;&#x7814;&#x53D1;&#x5FAE;&#x578B;&#x6C14;&#x76F8;&#x8272;&#x8C31;&#x6CD5; (&mu;GC) &#x7684;&#x5E94;&#x7528;&#x7A0B;&#x5E8F;&#x5FEB;&#x901F;&#x3001; &#x654F;&#x611F;&#x3001; &#x96C6;&#x6210;&#x5149;&#x5B66;&#x84B8;&#x6C14;&#x4F20;&#x611F;&#x5668;&#x9635;&#x5217;&#x7684;&#x7279;&#x70B9;&#x3002;&#x4F20;&#x611F;&#x5668;&#x57FA;&#x4E8E;&#x7531;&#x5FAE;&#x7C73;&#x8584;&#x84B8;&#x6C7D;&#x654F;&#x611F;&#x805A;&#x5408;&#x7269;&#x6D82;&#x5C42;&#x5728;&#x7845;&#x7247;&#x4E0A;&#x5F62;&#x6210;&#x7684;&#x5E72;&#x6D89;&#x6CD5;&#x5E03;&#x91CC;-P&eacute;rot (FP)&#x3002;&#x539A;&#x5EA6;&#x548C;&#x805A;&#x5408;&#x7269;&#x7684;&#x6298;&#x5C04;&#x7387;&#x4E0D;&#x540C;&#x53D8;&#x5316;&#x9020;&#x6210;&#x7684;&#x51B2;&#x51FB;&#x5BF9;&#x4F20;&#x611F;&#x5668;&#x7684;&#x6FC0;&#x5149;&#x53CD;&#x5C04;&#x5F3A;&#x5EA6;&#x7684;&#x84B8;&#x6C14;&#x5206;&#x6790;&#x7269;&#x7684;&#x54CD;&#x5E94;&#x3002;&#x6211;&#x4EEC;&#x7684;&#x7814;&#x7A76;&#xFF0C;&#x5728;&#x56DB;&#x4E2A;&#x4E0D;&#x540C;&#x805A;&#x5408;&#x7269;&#x88AB;&#x6D82; pre-etched &#x7845;&#x7247;&#xFF0C;&#x5F62;&#x6210;&#x7A7A;&#x95F4;&#x4E0A;&#x9694;&#x5F00;&#x7684;&#x4F20;&#x611F;&#x5668;&#x9635;&#x5217;&#x4E0A;&#x7684;&#x56DB;&#x53E3;&#x6C34;&#x4E95;&#x3002;CMOS &#x56FE;&#x50CF;&#x4F20;&#x611F;&#x5668;&#x88AB;&#x96C7;&#x7528;&#xFF0C;&#x540C;&#x65F6;&#x76D1;&#x6D4B;&#x805A;&#x5408;&#x7269;&#x7684;&#x53CD;&#x5E94;&#xFF0C;&#x4ECE;&#x800C;&#x4F7F;&#x591A;&#x8DEF;&#x590D;&#x7528;&#x901A;&#x8FC7;&#x6C14;&#x76F8;&#x8272;&#x8C31;&#x67F1;&#x6C14;&#x76F8;&#x5206;&#x6790;&#x7269;&#x7684;&#x68C0;&#x6D4B;&#x3002;&#x8868;&#x73B0;&#x5728;&#x5B58;&#x53D6;&#x65F6;&#x95F4;&#x4F4E;&#x4E8E;&#x4E00;&#x68C0;&#x6D4B;&#x65F6;&#x95F4;&#x3002;&#x6B64;&#x5916;&#xFF0C;sub-picogram &#x68C0;&#x6D4B;&#x9650;&#xFF0C;&#x8FBE;&#x5230;&#x6570;&#x91CF;&#x7EA7;&#x6539;&#x5584;&#x8F83;&#x4EE5;&#x524D;&#x62A5;&#x544A;&#x7684;&#x7247;&#x4E0A;&#x84B8;&#x6C14;&#x4F20;&#x611F;&#x5668;&#x3002;

&#x5FEB;&#x901F;&#x3001; &#x654F;&#x611F;&#x548C;&#x591A;&#x8DEF;&#x590D;&#x7528;&#x82AF;&#x7247;&#x5149;&#x5B66;&#x4F20;&#x611F;&#x5668;&#x7684;&#x5FAE;&#x578B;&#x6C14;&#x76F8;&#x8272;&#x8C31;&#x6CD5;&#x3002;

We developed and characterized a rapid, sensitive and integrated optical vapor sensor array for micro-gas chromatography (Î¼GC) applications. The sensor is based on the Fabry-PÃ©rot (FP) interferometer formed by a micrometre-thin vapor-sensitive polymer layer coated on a silicon wafer. The thickness and the refractive index of the polymer vary in response to the vapor analyte, resulting in a change in the reflected intensity of the laser impinged on the sensor. In our study, four different polymers were coated on four wells pre-etched on a silicon wafer to form a spatially separated sensor array. A CMOS imager was employed to simultaneously monitor the polymers' response, thus enabling multiplexed detection of a vapor analyte passing through the GC column. A sub-second detection time was demonstrated. In addition, a sub-picogram detection limit was achieved, representing orders of magnitude improvement over the on-chip vapor sensors previously reported.

Rapid, sensitive, and multiplexed on-chip optical sensors for micro-gas chromatography.

Nous avons d&eacute;velopp&eacute; et caract&eacute;ris&eacute; un capteurs de vapeur optique rapide, sensible et int&eacute;gr&eacute;e pour les applications de la chromatographie gaz-micro (&mu;GC). Le capteur est bas&eacute; sur l&#39;interf&eacute;rom&egrave;tre de Fabry-P&eacute;rot (FP), form&eacute; par une couche de polym&egrave;re sensibles &agrave; vapeur microm&egrave;tre-mince enduite sur une plaquette de silicium. L&#39;&eacute;paisseur et l&#39;indice de r&eacute;fraction du polym&egrave;re varient en r&eacute;ponse &agrave; l&#39;analyte vapor, conduisant &agrave; un changement dans l&#39;intensit&eacute; r&eacute;fl&eacute;chie du laser empi&eacute;t&eacute; sur le capteur. Dans notre &eacute;tude, quatre diff&eacute;rents polym&egrave;res ont &eacute;t&eacute; rev&ecirc;tus sur quatre puits pre-etched sur une plaquette de silicium pour former un tableau capteur spatialement s&eacute;par&eacute;s. Un imageur CMOS a &eacute;t&eacute; employ&eacute; pour contr&ocirc;ler simultan&eacute;ment la r&eacute;ponse des polym&egrave;res, permettant ainsi multiplex&eacute;es d&eacute;tection d&#39;un analyte de vapeur en passant par la colonne GC. Un temps inf&eacute;rieur de d&eacute;tection a &eacute;t&eacute; d&eacute;montr&eacute;. En outre, une limite de d&eacute;tection de sub-picogram a &eacute;t&eacute; atteint, repr&eacute;sentant am&eacute;lioration des ordres de grandeur sur les capteurs de vapeur sur puce signal&eacute;s auparavant.

Rapides, sensibles et multiplex&eacute;es sur puce capteurs optiques pour la chromatographie en phase gazeuse-micro.

Wir entwickelt und zeichnet sich eine schnelle, vertrauliche und integrierte optische Dampf-Sensor-Array f&uuml;r Mikro-Gas-Chromatographie (&mu;GC) Anwendungen. Der Sensor basiert auf der Fabry-P&eacute;rot (FP)-Interferometer, gebildet von einem Mikrometer d&uuml;nne Dampf-Sensitive Polymerschicht &uuml;berzogen auf einem Silizium-Wafer. Der Dicke und dem Brechungsindex des Polymers variieren in Reaktion auf Dampf Analyten, was eine &Auml;nderung in der reflektierten Intensit&auml;t der Laser-Eingriff auf dem Sensor. In unserer Studie wurden vier verschiedene Polymere vier Brunnen auf einem Silizium-Wafer bilden eine r&auml;umlich getrennter Sensor-Array pre-etched beschichtet. Ein CMOS-Imager wurde eingesetzt, um gleichzeitig die Polymers Antwort zu &uuml;berwachen, wodurch Multiplex-Erkennung einer Dampf-Analyten durch die GC-Spalte. Eine schnellere Erkennungszeit zeigte. Dar&uuml;ber hinaus wurde eine Sub-picogram-Nachweisgrenze erreicht, Gr&ouml;&szlig;enordnungen Verbesserung darstellt, &uuml;ber die auf dem Chip-Dunst-Sensoren, die zuvor gemeldet.

Raschen, vertraulichen und Multiplex auf dem Chip optische Sensoren f&uuml;r die Mikro-Gas-Chromatographie.

Abbiamo sviluppato e caratterizzato una serie di sensori vapor ottico rapida, sensibile e integrato per applicazioni micro-gas cromatografia (&mu;GC). Il sensore &egrave; basato sull&#39;interferometro di Fabry-P&eacute;rot (FP) formata da uno strato di polimero sensibile vapor micrometri-sottile ricoperto su un wafer di silicio. Lo spessore e l&#39;indice di rifrazione del polimero variano in risposta all&#39;analita vapor, risultante in un cambiamento dell&#39;intensit&agrave; riflessa del laser impinged sul sensore. Nel nostro studio, quattro diversi polimeri sono stati rivestiti su quattro pozzi pre-etched su un wafer di silicio per formare una serie di sensori spazialmente separati. Un CMOS imager &egrave; stato impiegato per monitorare simultaneamente la risposta dei polimeri, consentendo in tal modo multiplexed rilevazione di un analita vapor passando attraverso la colonna GC. &Egrave; stato dimostrato un tempo di rilevamento inferiori al secondo. Inoltre, &egrave; stato raggiunto un limite di rilevazione di sub-picogram, che rappresenta il miglioramento di ordini di grandezza sopra i sensori on-chip vapor precedentemente segnalati.

Rapide, sensibile e multiplex su chip sensori ottici per micro-gas cromatografia.

&#x6211;&#x3005; &#x306F;&#x958B;&#x767A;&#x3057;&#x3001;&#x6025;&#x901F;&#x306A;&#x654F;&#x611F;&#x306A;&#x7D71;&#x5408;&#x3055;&#x308C;&#x305F;&#x5149;&#x5B66;&#x5F0F;&#x84B8;&#x6C17;&#x30BB;&#x30F3;&#x30B5;&#x30FC; &#x30A2;&#x30EC;&#x30A4; &#x30DE;&#x30A4;&#x30AF;&#x30ED; &#x30AC;&#x30B9;&#x30AF;&#x30ED;&#x30DE;&#x30C8;&#x30B0;&#x30E9;&#x30D5;&#x30A3;&#x30FC; (&mu;GC) &#x30A2;&#x30D7;&#x30EA;&#x30B1;&#x30FC;&#x30B7;&#x30E7;&#x30F3;&#x306E;&#x7279;&#x5FB4;&#x3068;&#x3002;&#x30BB;&#x30F3;&#x30B5;&#x30FC;&#x306F;&#x3001;&#x30A6;&#x30A7;&#x30FC;&#x30CF;&#x306E;&#x30DE;&#x30A4;&#x30AF;&#x30ED; &#x30E1;&#x30FC;&#x30C8;&#x30EB;&#x8584;&#x3044;&#x84B8;&#x6C17;&#x611F;&#x53D7;&#x6027;&#x30DD;&#x30EA;&#x30DE;&#x30FC;&#x5C64;&#x306B;&#x3088;&#x3063;&#x3066;&#x5F62;&#x6210;&#x3055;&#x308C;&#x305F;&#x30D5;&#x30A1;&#x30D6;&#x30EA; &#x30FB; &#x30DA;&#x30ED;&#x30FC; (FP) &#x5E72;&#x6E09;&#x8A08;&#x306B;&#x57FA;&#x3065;&#x3044;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x30DD;&#x30EA;&#x30DE;&#x30FC;&#x306E;&#x5C48;&#x6298;&#x7387;&#x3068;&#x539A;&#x3055;&#x30BB;&#x30F3;&#x30B5;&#x30FC;&#x306B;&#x5165;&#x5C04;&#x30EC;&#x30FC;&#x30B6;&#x30FC;&#x306E;&#x53CD;&#x5C04;&#x5149;&#x5F37;&#x5EA6;&#x306E;&#x5909;&#x5316;&#x306E;&#x7D50;&#x679C;&#x3001;&#x84B8;&#x6C17; analyte &#x306E;&#x5FDC;&#x7B54;&#x306B;&#x3088;&#x3063;&#x3066;&#x7570;&#x306A;&#x308A;&#x307E;&#x3059;&#x3002;&#x79C1;&#x305F;&#x3061;&#x306E;&#x7814;&#x7A76;&#x3067;&#x306F;&#x3001;4 &#x3064;&#x306E;&#x7570;&#x306A;&#x308B;&#x30DD;&#x30EA;&#x30DE;&#x30FC;&#x7A7A;&#x3044;&#x305F;&#x8907;&#x6570;&#x30BB;&#x30F3;&#x30B5;&#x30FC; &#x30A2;&#x30EC;&#x30A4;&#x3092;&#x5F62;&#x6210;&#x3059;&#x308B;&#x30B7;&#x30EA;&#x30B3;&#x30F3;&#x30A6;&#x30A7;&#x30CF;&#x4E0A; pre-etched 4 &#x3064;&#x306E;&#x4E95;&#x6238;&#x3067;&#x88AB;&#x8986;&#x3055;&#x308C;&#x3066;&#x3044;&#x305F;&#x3002;CMOS &#x30A4;&#x30E1;&#x30FC;&#x30B8;&#x30E3; &#x30DD;&#x30EA;&#x30DE;&#x30FC;&#x306F;&#x3001;&#x5FDC;&#x7B54;&#x3092;&#x540C;&#x6642;&#x306B;&#x76E3;&#x8996;&#x3059;&#x308B;&#x63A1;&#x7528;&#x3001;attribute-name &#x591A;&#x91CD; GC &#x30AB;&#x30E9;&#x30E0;&#x3092;&#x901A;&#x3057;&#x3066;&#x3092;&#x6E21;&#x3059;&#x6C17;&#x76F8;&#x8A66;&#x6599;&#x306E;&#x691C;&#x51FA;&#x3002;1 &#x79D2;&#x672A;&#x6E80;&#x306E;&#x691C;&#x51FA;&#x6642;&#x9593;&#x304C;&#x5B9F;&#x8A3C;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x3055;&#x3089;&#x306B;&#x3001;&#x4EE5;&#x524D;&#x5831;&#x544A;&#x3057;&#x305F;&#x30AA;&#x30F3;&#x30C1;&#x30C3;&#x30D7;&#x84B8;&#x6C17;&#x30BB;&#x30F3;&#x30B5;&#x30FC;&#x3092;&#x4ECB;&#x3057;&#x3066;&#x6841;&#x9055;&#x3044;&#x306B;&#x6539;&#x5584;&#x3092;&#x8868;&#x3059; sub-picogram &#x306E;&#x691C;&#x51FA;&#x9650;&#x754C;&#x304C;&#x9054;&#x6210;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;

&#x8FC5;&#x901F;&#x3001;&#x654F;&#x611F;&#x3067;&#x3001;&#x591A;&#x91CD;&#x306E;&#x30AA;&#x30F3;&#x30C1;&#x30C3;&#x30D7;&#x5149;&#x30BB;&#x30F3;&#x30B5;&#x30FC; &#x30DE;&#x30A4;&#x30AF;&#x30ED; &#x30AC;&#x30B9;&#x30AF;&#x30ED;&#x30DE;&#x30C8;&#x30B0;&#x30E9;&#x30D5;&#x30A3;&#x30FC;&#x7528;&#x3002;

&#xC6B0;&#xB9AC;&#xAC00; &#xAC1C;&#xBC1C; &#xD558; &#xACE0; &#xB9C8;&#xC774;&#xD06C;&#xB85C; &#xAC00;&#xC2A4; &#xD06C;&#xB85C;&#xB9C8;&#xD1A0;&#xADF8;&#xB798;&#xD53C; (&mu;GC) &#xC751;&#xC6A9; &#xD504;&#xB85C;&#xADF8;&#xB7A8;&#xC5D0; &#xB300; &#xD55C; &#xBE60;&#xB974;&#xACE0; &#xBBFC;&#xAC10;&#xD55C; &#xD1B5;&#xD569; &#xAD11;&#xD559; &#xC99D;&#xAE30; &#xC13C;&#xC11C; &#xC5B4;&#xB808;&#xC774; &#xD2B9;&#xC9D5;. &#xC13C;&#xC11C; &#xB9C8;&#xC774;&#xD06C;&#xB85C;&#xBBF8;&#xD130; &#xC587;&#xC740; &#xC99D;&#xAE30; &#xBBFC;&#xAC10;&#xD55C; &#xD3F4;&#xB9AC;&#xBA38; &#xB808;&#xC774;&#xC5B4; &#xC2E4;&#xB9AC;&#xCF58; &#xC6E8;&#xC774;&#xD37C;&#xC5D0; &#xCF54;&#xD305;&#xC5D0; &#xC758;&#xD574; &#xD615;&#xC131; &#xB41C; Fabry-P&eacute;rot (FP) &#xAC04;&#xC12D;&#xACC4;&#xB97C; &#xAE30;&#xBC18;&#xC73C;&#xB85C; &#xD569;&#xB2C8;&#xB2E4;. &#xB450;&#xAED8; &#xD3F4;&#xB9AC;&#xBA38;&#xC758; &#xAD74;&#xC808;&#xB960; &#xC13C;&#xC11C;&#xC5D0; impinged &#xB808;&#xC774;&#xC800;&#xC758; &#xBC18;&#xC0AC; &#xAC15;&#xB3C4; &#xBCC0;&#xD654;&#xC5D0; &#xB530;&#xB978; &#xAE30;&#xC0C1; &#xBD84;&#xC11D;&#xC5D0; &#xB300; &#xD55C; &#xC751;&#xB2F5;&#xC5D0; &#xB530;&#xB77C; &#xB2E4;&#xB985;&#xB2C8;&#xB2E4;. &#xC6B0;&#xB9AC;&#xC758; &#xC5F0;&#xAD6C;&#xC5D0;&#xC11C; &#xACF5;&#xAC04;&#xC801;&#xC73C;&#xB85C; &#xBD84;&#xB9AC; &#xB41C; &#xC13C;&#xC11C; &#xBC30;&#xC5F4;&#xC744; &#xAD6C;&#xC131; &#xC2E4;&#xB9AC;&#xCF58; &#xC6E8;&#xC774;&#xD37C;&#xC5D0; pre-etched 4 &#xAC1C;&#xC758; &#xC6B0;&#xBB3C;&#xC5D0; 4 &#xAC1C;&#xC758; &#xB2E4;&#xB978; &#xACE0;&#xBD84;&#xC790; &#xCF54;&#xD305; &#xD588;&#xB2E4;. CMOS &#xC601;&#xC0C1; &#xACE0;&#xBD84;&#xC790;&#xC758; &#xC751;&#xB2F5;&#xC744; &#xB3D9;&#xC2DC;&#xC5D0; &#xBAA8;&#xB2C8;&#xD130;&#xB9C1;&#xC744; &#xACE0;&#xC6A9; &#xD588;&#xB2E4;, GC &#xC5F4; &#xD1B5;&#xACFC; &#xC99D;&#xAE30; &#xC2E4;&#xC815;&#xC774; &#xD0D0;&#xC9C0; &#xB2E4;&#xC911;&#xD654;&#xB97C; &#xD65C;&#xC131;&#xD654; &#xD569;&#xB2C8;&#xB2E4;. &#xB9CE;&#xC544;&#xB3C4; &#xD0D0;&#xC9C0; &#xC2DC;&#xAC04; &#xC2DC;&#xC5F0; &#xD588;&#xB2E4;. &#xB610;&#xD55C;, &#xC774;&#xC804;&#xC5D0; &#xBCF4;&#xACE0; &#xB41C; &#xCE69;&#xC5D0; &#xAE30;&#xC0C1; &#xC13C;&#xC11C;&#xB97C; &#xD1B5;&#xD574; &#xBC30;&#xB098; &#xD5A5;&#xC0C1;&#xC744; &#xB098;&#xD0C0;&#xB0B4;&#xB294; sub-picogram &#xAC80;&#xCD9C; &#xD55C;&#xACC4; &#xB2EC;&#xC131; &#xD588;&#xB2E4;.

&#xBE60;&#xB978;, &#xBBFC;&#xAC10;&#xD55C;, &#xADF8;&#xB9AC;&#xACE0; &#xB2E4;&#xC911;&#xD654; &#xB0B4;&#xC7A5; &#xAD11; &#xC13C;&#xC11C; &#xB9C8;&#xC774;&#xD06C;&#xB85C; &#xAC00;&#xC2A4; &#xD06C;&#xB85C;&#xB9C8;&#xD1A0;&#xADF8;&#xB798;&#xD53C;&#xC5D0; &#xB300; &#xD55C;.

Hemos desarrollado y hab&iacute;a caracterizado un arsenal de sensor de vapor &oacute;ptica r&aacute;pida, sensible e integrado para aplicaciones de micro-cromatograf&iacute;a (&mu;GC). El sensor se basa en el interfer&oacute;metro de Fabry-P&eacute;rot (FP), formado por una capa de pol&iacute;mero sensible a vapor micr&oacute;metros-fina cubierta en una oblea de silicio. El espesor y el &iacute;ndice de refracci&oacute;n del pol&iacute;mero var&iacute;an en respuesta a vapor analito, dando por resultado un cambio en la intensidad reflejada del afectado en el sensor l&aacute;ser. En nuestro estudio, cuatro diferentes pol&iacute;meros se cubrieron en cuatro pozos pre-etched sobre una oblea de silicio para formar una matriz de sensor espacial separado. Un sensor CMOS fue empleado para vigilar simult&aacute;neamente la respuesta de los pol&iacute;meros, permitiendo hab&iacute;a multiplexado detecci&oacute;n de un analito de vapor pasa a trav&eacute;s de la columna de la GC. Se demostr&oacute; un tiempo de detecci&oacute;n de fracciones de segundos. Adem&aacute;s, se logr&oacute; un l&iacute;mite de detecci&oacute;n de sub-picogram, que representa mejora de &oacute;rdenes de magnitud sobre los sensores de la en-viruta vapor divulgados previamente.

R&aacute;pida, sensibles y multiplexados en-viruta sensores &oacute;pticos para cromatograf&iacute;a de gases-micro.

Bio-switchable optofluidic lasers based on DNA Holliday junctions were demonstrated. Nearly 100% wavelength switching was achieved through reversible conformational change of the Holliday junction controlled by magnesium ionic strength.

Bio-switchable optofluidic lasers based on DNA Holliday junctions.

DNA melting analysis holds great promise for simple and fast DNA sequence discrimination. However, conventional fluorescence-based methods suffer from a small differential signal and demanding melting curve analysis, both of which make it difficult to distinguish the target DNA from the mismatched one. Herein, we propose and demonstrate a highly specific intracavity DNA melting analysis scheme utilizing an optofluidic laser. The laser optically amplifies the small yet intrinsic thermal dynamic difference between the target and the single-base-mismatched DNA, resulting in a differential signal that is orders of magnitude greater than with fluorescence-based methods. In particular, the existence of a phase transition between the stimulated laser emission and fluorescence (i.e., spontaneous emission) enables accurate determination of the DNA transition temperature difference. Furthermore, the high differential signal in the intracavity detection allows for scanning of the laser excitation at a fixed temperature to distinguish two DNA sequences, which provides another means for rapid DNA analysis. In this paper, we first theoretically investigate DNA melting analysis using an optofluidic laser and then experimentally explore this scheme with a high-quality optofluidic ring resonator. Distinction of two DNA sequences of up to 100 bases long is demonstrated. The intracavity detection developed here will lead to novel optofluidic devices that enable rapid and simple analysis of DNAs with very long sequences.

Intracavity DNA melting analysis with optofluidic lasers.

Cavity optomechanics allows the parametric coupling of phonon- and photon-modes in microresonators and is presently investigated in a broad variety of solid-state systems. Optomechanics with superfluids has been proposed as a path towards ultra-low optical- and mechanical-dissipation. However, there have been no optomechanics experiments reported with non-solid phases of matter. Direct liquid immersion of optomechanics experiments is challenging, as the acoustic energy simply leaks out to the higher-impedance liquid surrounding the device. Here we confine liquids within hollow resonators to circumvent this issue and to enable optical excitation of mechanical whispering-gallery modes at frequencies ranging from 2 to 11,000 MHz. Our device enables optomechanical investigation with liquids, while light is conventionally coupled from the outer dry side of the capillary, and liquids are provided by means of a standard microfluidic inlet.

Brillouin cavity optomechanics with microfluidic devices.

We have applied self-assembled DNA tetrahedral nanostructures for the precise and tunable control of the gain in an optofluidic fluorescence resonance energy transfer (FRET) laser. By adjusting the ratio of the donor and the acceptor attached to the tetrahedral vertices, 3.8 times reduction in the lasing threshold and 28-fold enhancement in the lasing efficiency were demonstrated. This work takes advantage of the self-recognition and self-assembly capabilities of biomolecules with well-defined structures and addressability, enabling nano-engineering of the laser down to the molecular level.

Article	Year
Demonstration of the coupling of optofluidic ring resonator lasers with liquid waveguides. Optics letters\| PubMed ID: 20808395	2010
Versatile optofluidic ring resonator lasers based on microdroplets. Optics express\| PubMed ID: 21996908	2011
Rapid, sensitive, and multiplexed on-chip optical sensors for micro-gas chromatography. Lab on a chip\| PubMed ID: 22245960	2012
Bio-switchable optofluidic lasers based on DNA Holliday junctions. Lab on a chip\| PubMed ID: 22790530	2012
Intracavity DNA melting analysis with optofluidic lasers. Analytical chemistry\| PubMed ID: 23017119	2012
Brillouin cavity optomechanics with microfluidic devices. Nature communications\| PubMed ID: 23744103	2013
Self-assembled DNA tetrahedral optofluidic lasers with precise and tunable gain control. Lab on a chip\| PubMed ID: 23846506	2013

Wonsuk Lee

Biography

JoVE Journal Publications

Other Publications